* [syzbot] [net?] possible deadlock in inet_shutdown
@ 2025-09-05 20:00 syzbot
2025-09-05 20:03 ` Eric Dumazet
0 siblings, 1 reply; 11+ messages in thread
From: syzbot @ 2025-09-05 20:00 UTC (permalink / raw)
To: axboe, davem, dsahern, edumazet, horms, kuba, linux-block,
linux-kernel, ming.lei, netdev, pabeni, syzkaller-bugs,
thomas.hellstrom
Hello,
syzbot found the following issue on:
HEAD commit: 788bc43d8330 Merge branch 'microchip-lan865x-fix-probing-i..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=10fc4e34580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9c302bcfb26a48af
dashboard link: https://syzkaller.appspot.com/bug?extid=e1cd6bd8493060bd701d
compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=136c41f0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13bac242580000
Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/c958eee3370d/disk-788bc43d.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/615040093399/vmlinux-788bc43d.xz
kernel image: https://storage.googleapis.com/syzbot-assets/91377e9f5c93/bzImage-788bc43d.xz
The issue was bisected to:
commit ffa1e7ada456087c2402b37cd6b2863ced29aff0
Author: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Date: Tue Mar 18 09:55:48 2025 +0000
block: Make request_queue lockdep splats show up earlier
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1263c1f0580000
final oops: https://syzkaller.appspot.com/x/report.txt?x=1163c1f0580000
console output: https://syzkaller.appspot.com/x/log.txt?x=1663c1f0580000
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com
Fixes: ffa1e7ada456 ("block: Make request_queue lockdep splats show up earlier")
block nbd0: Send control failed (result -89)
block nbd0: Request send failed, requeueing
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Not tainted
------------------------------------------------------
udevd/5878 is trying to acquire lock:
ffff88807ba3eed8 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline]
ffff88807ba3eed8 (sk_lock-AF_INET6){+.+.}-{0:0}, at: inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
but task is already holding lock:
ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_queue_rq+0xa66/0xf10 drivers/block/nbd.c:1204
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #6 (&nsock->tx_lock){+.+.}-{4:4}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:598 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
nbd_queue_rq+0x257/0xf10 drivers/block/nbd.c:1204
blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
blk_finish_plug block/blk-core.c:1247 [inline]
__submit_bio+0x2d3/0x5a0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
submit_bh fs/buffer.c:2829 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2447
filemap_read_folio+0x114/0x380 mm/filemap.c:2413
do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
read_mapping_folio include/linux/pagemap.h:991 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:748
bdev_open+0x31e/0xd30 block/bdev.c:957
blkdev_open+0x3a8/0x510 block/fops.c:691
do_dentry_open+0x950/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #5 (&cmd->lock){+.+.}-{4:4}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:598 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196
blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
blk_finish_plug block/blk-core.c:1247 [inline]
__submit_bio+0x2d3/0x5a0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
submit_bh fs/buffer.c:2829 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2447
filemap_read_folio+0x114/0x380 mm/filemap.c:2413
do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
read_mapping_folio include/linux/pagemap.h:991 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:748
bdev_open+0x31e/0xd30 block/bdev.c:957
blkdev_open+0x3a8/0x510 block/fops.c:691
do_dentry_open+0x950/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #4 (set->srcu){.+.+}-{0:0}:
lock_sync+0xba/0x160 kernel/locking/lockdep.c:5916
srcu_lock_sync include/linux/srcu.h:173 [inline]
__synchronize_srcu+0x96/0x3a0 kernel/rcu/srcutree.c:1429
elevator_switch+0x12b/0x640 block/elevator.c:588
elevator_change+0x2d4/0x450 block/elevator.c:690
elevator_set_default+0x186/0x260 block/elevator.c:766
blk_register_queue+0x34e/0x3f0 block/blk-sysfs.c:904
__add_disk+0x677/0xd50 block/genhd.c:528
add_disk_fwnode+0xfc/0x480 block/genhd.c:597
add_disk include/linux/blkdev.h:774 [inline]
nbd_dev_add+0x717/0xae0 drivers/block/nbd.c:1973
nbd_init+0x168/0x1f0 drivers/block/nbd.c:2680
do_one_initcall+0x233/0x820 init/main.c:1269
do_initcall_level+0x104/0x190 init/main.c:1331
do_initcalls+0x59/0xa0 init/main.c:1347
kernel_init_freeable+0x334/0x4b0 init/main.c:1579
kernel_init+0x1d/0x1d0 init/main.c:1469
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #3 (&q->elevator_lock){+.+.}-{4:4}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:598 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
elevator_change+0x19b/0x450 block/elevator.c:688
elevator_set_none+0x42/0xb0 block/elevator.c:781
blk_mq_elv_switch_none block/blk-mq.c:5023 [inline]
__blk_mq_update_nr_hw_queues block/blk-mq.c:5066 [inline]
blk_mq_update_nr_hw_queues+0x598/0x1aa0 block/blk-mq.c:5124
nbd_start_device+0x17f/0xb10 drivers/block/nbd.c:1478
nbd_genl_connect+0x135b/0x18f0 drivers/block/nbd.c:2228
genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115
genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:729
____sys_sendmsg+0x505/0x830 net/socket.c:2614
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
__sys_sendmsg net/socket.c:2700 [inline]
__do_sys_sendmsg net/socket.c:2705 [inline]
__se_sys_sendmsg net/socket.c:2703 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #2 (&q->q_usage_counter(io)#49){++++}-{0:0}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
blk_alloc_queue+0x538/0x620 block/blk-core.c:461
blk_mq_alloc_queue block/blk-mq.c:4400 [inline]
__blk_mq_alloc_disk+0x15c/0x340 block/blk-mq.c:4447
nbd_dev_add+0x46c/0xae0 drivers/block/nbd.c:1943
nbd_init+0x168/0x1f0 drivers/block/nbd.c:2680
do_one_initcall+0x233/0x820 init/main.c:1269
do_initcall_level+0x104/0x190 init/main.c:1331
do_initcalls+0x59/0xa0 init/main.c:1347
kernel_init_freeable+0x334/0x4b0 init/main.c:1579
kernel_init+0x1d/0x1d0 init/main.c:1469
ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
-> #1 (fs_reclaim){+.+.}-{0:0}:
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
__fs_reclaim_acquire mm/page_alloc.c:4234 [inline]
fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4248
might_alloc include/linux/sched/mm.h:318 [inline]
slab_pre_alloc_hook mm/slub.c:4131 [inline]
slab_alloc_node mm/slub.c:4209 [inline]
kmem_cache_alloc_node_noprof+0x47/0x3c0 mm/slub.c:4281
__alloc_skb+0x112/0x2d0 net/core/skbuff.c:659
alloc_skb include/linux/skbuff.h:1336 [inline]
__ip6_append_data+0x2c16/0x3f30 net/ipv6/ip6_output.c:1671
ip6_append_data+0x1c4/0x380 net/ipv6/ip6_output.c:1860
rawv6_sendmsg+0x127a/0x1820 net/ipv6/raw.c:911
sock_sendmsg_nosec net/socket.c:714 [inline]
__sock_sendmsg+0x19c/0x270 net/socket.c:729
____sys_sendmsg+0x505/0x830 net/socket.c:2614
___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
__sys_sendmsg net/socket.c:2700 [inline]
__do_sys_sendmsg net/socket.c:2705 [inline]
__se_sys_sendmsg net/socket.c:2703 [inline]
__x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (sk_lock-AF_INET6){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
lock_sock_nested+0x48/0x100 net/core/sock.c:3733
lock_sock include/net/sock.h:1667 [inline]
inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
nbd_send_cmd+0x11ec/0x1ba0 drivers/block/nbd.c:799
nbd_handle_cmd drivers/block/nbd.c:1174 [inline]
nbd_queue_rq+0xcdb/0xf10 drivers/block/nbd.c:1204
blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
blk_finish_plug block/blk-core.c:1247 [inline]
__submit_bio+0x2d3/0x5a0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
submit_bh fs/buffer.c:2829 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2447
filemap_read_folio+0x114/0x380 mm/filemap.c:2413
do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
read_mapping_folio include/linux/pagemap.h:991 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:748
bdev_open+0x31e/0xd30 block/bdev.c:957
blkdev_open+0x3a8/0x510 block/fops.c:691
do_dentry_open+0x950/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
sk_lock-AF_INET6 --> &cmd->lock --> &nsock->tx_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&nsock->tx_lock);
lock(&cmd->lock);
lock(&nsock->tx_lock);
lock(sk_lock-AF_INET6);
*** DEADLOCK ***
4 locks held by udevd/5878:
#0: ffff8880250f6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
#1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
#1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
#1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2358
#2: ffff88805a2e0178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196
#3: ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
#3: ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_queue_rq+0xa66/0xf10 drivers/block/nbd.c:1204
stack backtrace:
CPU: 0 UID: 0 PID: 5878 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
<TASK>
dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
lock_sock_nested+0x48/0x100 net/core/sock.c:3733
lock_sock include/net/sock.h:1667 [inline]
inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
nbd_send_cmd+0x11ec/0x1ba0 drivers/block/nbd.c:799
nbd_handle_cmd drivers/block/nbd.c:1174 [inline]
nbd_queue_rq+0xcdb/0xf10 drivers/block/nbd.c:1204
blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
__blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
__blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
__blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
blk_finish_plug block/blk-core.c:1247 [inline]
__submit_bio+0x2d3/0x5a0 block/blk-core.c:649
__submit_bio_noacct_mq block/blk-core.c:722 [inline]
submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
submit_bh fs/buffer.c:2829 [inline]
block_read_full_folio+0x599/0x830 fs/buffer.c:2447
filemap_read_folio+0x114/0x380 mm/filemap.c:2413
do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
read_mapping_folio include/linux/pagemap.h:991 [inline]
read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
check_partition block/partitions/core.c:141 [inline]
blk_add_partitions block/partitions/core.c:589 [inline]
bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
blkdev_get_whole+0x380/0x510 block/bdev.c:748
bdev_open+0x31e/0xd30 block/bdev.c:957
blkdev_open+0x3a8/0x510 block/fops.c:691
do_dentry_open+0x950/0x13f0 fs/open.c:965
vfs_open+0x3b/0x340 fs/open.c:1095
do_open fs/namei.c:3887 [inline]
path_openat+0x2ee5/0x3830 fs/namei.c:4046
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1435
do_sys_open fs/open.c:1450 [inline]
__do_sys_openat fs/open.c:1466 [inline]
__se_sys_openat fs/open.c:1461 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1461
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6d8e8a7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffc70a60620 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f6d8f007880 RCX: 00007f6d8e8a7407
RDX: 00000000000a0800 RSI: 000056300ccb64f0 RDI: ffffffffffffff9c
RBP: 000056300cc95910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000056300ccc6350
R13: 000056300cca3190 R14: 0000000000000000 R15: 000056300ccc6350
</TASK>
I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 1, async page read
I/O error, dev nbd0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 2, async page read
I/O error, dev nbd0, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 3, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 1, async page read
I/O error, dev nbd0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 2, async page read
I/O error, dev nbd0, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 3, async page read
I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 0, async page read
I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd0, logical block 1, async page read
ldm_validate_partition_table(): Disk read failed.
Dev nbd0: unable to read RDB block 0
nbd0: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd0: unable to read RDB block 0
nbd0: unable to read partition table
block nbd2: Send control failed (result -89)
block nbd2: Request send failed, requeueing
block nbd2: Dead connection, failed to find a fallback
block nbd2: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd2: unable to read RDB block 0
nbd2: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd2: unable to read RDB block 0
nbd2: unable to read partition table
block nbd3: Send control failed (result -89)
block nbd3: Request send failed, requeueing
block nbd3: Dead connection, failed to find a fallback
block nbd3: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd3: unable to read RDB block 0
nbd3: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd3: unable to read RDB block 0
nbd3: unable to read partition table
block nbd4: Send control failed (result -89)
block nbd4: Request send failed, requeueing
ldm_validate_partition_table(): Disk read failed.
Dev nbd4: unable to read RDB block 0
nbd4: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd4: unable to read RDB block 0
nbd4: unable to read partition table
block nbd5: Send control failed (result -89)
block nbd5: Request send failed, requeueing
block nbd5: Dead connection, failed to find a fallback
ldm_validate_partition_table(): Disk read failed.
Dev nbd5: unable to read RDB block 0
nbd5: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd5: unable to read RDB block 0
nbd5: unable to read partition table
block nbd6: Send control failed (result -89)
block nbd6: Request send failed, requeueing
block nbd6: Dead connection, failed to find a fallback
block nbd6: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd6: unable to read RDB block 0
nbd6: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd6: unable to read RDB block 0
nbd6: unable to read partition table
block nbd7: Send control failed (result -89)
block nbd7: Request send failed, requeueing
ldm_validate_partition_table(): Disk read failed.
Dev nbd7: unable to read RDB block 0
nbd7: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd7: unable to read RDB block 0
nbd7: unable to read partition table
block nbd8: Send control failed (result -89)
block nbd8: Request send failed, requeueing
ldm_validate_partition_table(): Disk read failed.
Dev nbd8: unable to read RDB block 0
nbd8: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd8: unable to read RDB block 0
nbd8: unable to read partition table
block nbd9: Send control failed (result -32)
block nbd9: Request send failed, requeueing
ldm_validate_partition_table(): Disk read failed.
Dev nbd9: unable to read RDB block 0
nbd9: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd9: unable to read RDB block 0
nbd9: unable to read partition table
block nbd10: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd10: unable to read RDB block 0
nbd10: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd10: unable to read RDB block 0
nbd10: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd11: unable to read RDB block 0
nbd11: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd11: unable to read RDB block 0
nbd11: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd12: unable to read RDB block 0
nbd12: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd12: unable to read RDB block 0
nbd12: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd13: unable to read RDB block 0
nbd13: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd13: unable to read RDB block 0
nbd13: unable to read partition table
nbd_send_cmd: 5 callbacks suppressed
block nbd14: Send control failed (result -89)
nbd_send_cmd: 5 callbacks suppressed
block nbd14: Request send failed, requeueing
block nbd14: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd14: unable to read RDB block 0
nbd14: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd14: unable to read RDB block 0
nbd14: unable to read partition table
block nbd15: Send control failed (result -89)
block nbd15: Request send failed, requeueing
block nbd15: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd15: unable to read RDB block 0
nbd15: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd15: unable to read RDB block 0
nbd15: unable to read partition table
block nbd16: Send control failed (result -89)
block nbd16: Request send failed, requeueing
ldm_validate_partition_table(): Disk read failed.
Dev nbd16: unable to read RDB block 0
nbd16: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd16: unable to read RDB block 0
nbd16: unable to read partition table
block nbd17: Send control failed (result -89)
block nbd17: Request send failed, requeueing
ldm_validate_partition_table(): Disk read failed.
Dev nbd17: unable to read RDB block 0
nbd17: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd17: unable to read RDB block 0
nbd17: unable to read partition table
block nbd18: Send control failed (result -89)
block nbd18: Request send failed, requeueing
ldm_validate_partition_table(): Disk read failed.
Dev nbd18: unable to read RDB block 0
nbd18: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd18: unable to read RDB block 0
nbd18: unable to read partition table
block nbd19: Send control failed (result -89)
block nbd19: Request send failed, requeueing
block nbd19: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd19: unable to read RDB block 0
nbd19: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd19: unable to read RDB block 0
nbd19: unable to read partition table
block nbd20: Send control failed (result -89)
block nbd20: Request send failed, requeueing
block nbd20: Dead connection, failed to find a fallback
blk_print_req_error: 2802 callbacks suppressed
I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
buffer_io_error: 2802 callbacks suppressed
Buffer I/O error on dev nbd20, logical block 1, async page read
I/O error, dev nbd20, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd20, logical block 2, async page read
I/O error, dev nbd20, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd20, logical block 3, async page read
I/O error, dev nbd20, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd20, logical block 0, async page read
I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd20, logical block 1, async page read
I/O error, dev nbd20, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd20, logical block 2, async page read
I/O error, dev nbd20, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd20, logical block 3, async page read
I/O error, dev nbd20, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd20, logical block 0, async page read
I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
Buffer I/O error on dev nbd20, logical block 1, async page read
ldm_validate_partition_table(): Disk read failed.
Dev nbd20: unable to read RDB block 0
nbd20: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd20: unable to read RDB block 0
nbd20: unable to read partition table
block nbd21: Send control failed (result -89)
block nbd21: Request send failed, requeueing
block nbd21: Dead connection, failed to find a fallback
ldm_validate_partition_table(): Disk read failed.
Dev nbd21: unable to read RDB block 0
nbd21: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd21: unable to read RDB block 0
nbd21: unable to read partition table
block nbd22: Send control failed (result -89)
block nbd22: Request send failed, requeueing
ldm_validate_partition_table(): Disk read failed.
Dev nbd22: unable to read RDB block 0
nbd22: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd22: unable to read RDB block 0
nbd22: unable to read partition table
block nbd23: Send control failed (result -89)
block nbd23: Request send failed, requeueing
block nbd23: Dead connection, failed to find a fallback
ldm_validate_partition_table(): Disk read failed.
Dev nbd23: unable to read RDB block 0
nbd23: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd23: unable to read RDB block 0
nbd23: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd24: unable to read RDB block 0
nbd24: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd24: unable to read RDB block 0
nbd24: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd25: unable to read RDB block 0
nbd25: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd25: unable to read RDB block 0
nbd25: unable to read partition table
block nbd26: Dead connection, failed to find a fallback
ldm_validate_partition_table(): Disk read failed.
Dev nbd26: unable to read RDB block 0
nbd26: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd26: unable to read RDB block 0
nbd26: unable to read partition table
block nbd27: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd27: unable to read RDB block 0
nbd27: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd27: unable to read RDB block 0
nbd27: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd28: unable to read RDB block 0
nbd28: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd28: unable to read RDB block 0
nbd28: unable to read partition table
block nbd29: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd29: unable to read RDB block 0
nbd29: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd29: unable to read RDB block 0
nbd29: unable to read partition table
block nbd30: shutting down sockets
ldm_validate_partition_table(): Disk read failed.
Dev nbd30: unable to read RDB block 0
nbd30: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd30: unable to read RDB block 0
nbd30: unable to read partition table
ldm_validate_partition_table(): Disk read failed.
Dev nbd31: unable to read RDB block 0
nbd31: unable to read partition table
---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.
syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title
If you want syzbot to run the reproducer, reply with:
#syz test: git://repo/address.git branch-or-commit-hash
If you attach or paste a git patch, syzbot will apply it before testing.
If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)
If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report
If you want to undo deduplication, reply with:
#syz undup
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-05 20:00 [syzbot] [net?] possible deadlock in inet_shutdown syzbot
@ 2025-09-05 20:03 ` Eric Dumazet
2025-09-06 9:16 ` Eric Dumazet
2025-09-08 14:26 ` Jens Axboe
0 siblings, 2 replies; 11+ messages in thread
From: Eric Dumazet @ 2025-09-05 20:03 UTC (permalink / raw)
To: syzbot, Josef Bacik, Jens Axboe
Cc: davem, dsahern, horms, kuba, linux-block, linux-kernel, ming.lei,
netdev, pabeni, syzkaller-bugs, thomas.hellstrom
On Fri, Sep 5, 2025 at 1:00 PM syzbot
<syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
>
> Hello,
>
> syzbot found the following issue on:
>
> HEAD commit: 788bc43d8330 Merge branch 'microchip-lan865x-fix-probing-i..
> git tree: net
> console output: https://syzkaller.appspot.com/x/log.txt?x=10fc4e34580000
> kernel config: https://syzkaller.appspot.com/x/.config?x=9c302bcfb26a48af
> dashboard link: https://syzkaller.appspot.com/bug?extid=e1cd6bd8493060bd701d
> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=136c41f0580000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13bac242580000
>
> Downloadable assets:
> disk image: https://storage.googleapis.com/syzbot-assets/c958eee3370d/disk-788bc43d.raw.xz
> vmlinux: https://storage.googleapis.com/syzbot-assets/615040093399/vmlinux-788bc43d.xz
> kernel image: https://storage.googleapis.com/syzbot-assets/91377e9f5c93/bzImage-788bc43d.xz
>
> The issue was bisected to:
>
> commit ffa1e7ada456087c2402b37cd6b2863ced29aff0
> Author: Thomas Hellström <thomas.hellstrom@linux.intel.com>
> Date: Tue Mar 18 09:55:48 2025 +0000
>
> block: Make request_queue lockdep splats show up earlier
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1263c1f0580000
> final oops: https://syzkaller.appspot.com/x/report.txt?x=1163c1f0580000
> console output: https://syzkaller.appspot.com/x/log.txt?x=1663c1f0580000
>
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com
> Fixes: ffa1e7ada456 ("block: Make request_queue lockdep splats show up earlier")
>
> block nbd0: Send control failed (result -89)
> block nbd0: Request send failed, requeueing
> ======================================================
> WARNING: possible circular locking dependency detected
> syzkaller #0 Not tainted
> ------------------------------------------------------
> udevd/5878 is trying to acquire lock:
> ffff88807ba3eed8 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline]
> ffff88807ba3eed8 (sk_lock-AF_INET6){+.+.}-{0:0}, at: inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
>
> but task is already holding lock:
> ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
> ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_queue_rq+0xa66/0xf10 drivers/block/nbd.c:1204
>
> which lock already depends on the new lock.
>
>
> the existing dependency chain (in reverse order) is:
>
> -> #6 (&nsock->tx_lock){+.+.}-{4:4}:
> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
> __mutex_lock_common kernel/locking/mutex.c:598 [inline]
> __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
> nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
> nbd_queue_rq+0x257/0xf10 drivers/block/nbd.c:1204
> blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
> __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
> blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
> __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
> blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
> blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
> blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
> blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
> __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
> blk_finish_plug block/blk-core.c:1247 [inline]
> __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
> __submit_bio_noacct_mq block/blk-core.c:722 [inline]
> submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
> submit_bh fs/buffer.c:2829 [inline]
> block_read_full_folio+0x599/0x830 fs/buffer.c:2447
> filemap_read_folio+0x114/0x380 mm/filemap.c:2413
> do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
> read_mapping_folio include/linux/pagemap.h:991 [inline]
> read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
> adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
> check_partition block/partitions/core.c:141 [inline]
> blk_add_partitions block/partitions/core.c:589 [inline]
> bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
> blkdev_get_whole+0x380/0x510 block/bdev.c:748
> bdev_open+0x31e/0xd30 block/bdev.c:957
> blkdev_open+0x3a8/0x510 block/fops.c:691
> do_dentry_open+0x950/0x13f0 fs/open.c:965
> vfs_open+0x3b/0x340 fs/open.c:1095
> do_open fs/namei.c:3887 [inline]
> path_openat+0x2ee5/0x3830 fs/namei.c:4046
> do_filp_open+0x1fa/0x410 fs/namei.c:4073
> do_sys_openat2+0x121/0x1c0 fs/open.c:1435
> do_sys_open fs/open.c:1450 [inline]
> __do_sys_openat fs/open.c:1466 [inline]
> __se_sys_openat fs/open.c:1461 [inline]
> __x64_sys_openat+0x138/0x170 fs/open.c:1461
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> -> #5 (&cmd->lock){+.+.}-{4:4}:
> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
> __mutex_lock_common kernel/locking/mutex.c:598 [inline]
> __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
> nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196
> blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
> __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
> blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
> __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
> blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
> blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
> blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
> blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
> __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
> blk_finish_plug block/blk-core.c:1247 [inline]
> __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
> __submit_bio_noacct_mq block/blk-core.c:722 [inline]
> submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
> submit_bh fs/buffer.c:2829 [inline]
> block_read_full_folio+0x599/0x830 fs/buffer.c:2447
> filemap_read_folio+0x114/0x380 mm/filemap.c:2413
> do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
> read_mapping_folio include/linux/pagemap.h:991 [inline]
> read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
> adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
> check_partition block/partitions/core.c:141 [inline]
> blk_add_partitions block/partitions/core.c:589 [inline]
> bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
> blkdev_get_whole+0x380/0x510 block/bdev.c:748
> bdev_open+0x31e/0xd30 block/bdev.c:957
> blkdev_open+0x3a8/0x510 block/fops.c:691
> do_dentry_open+0x950/0x13f0 fs/open.c:965
> vfs_open+0x3b/0x340 fs/open.c:1095
> do_open fs/namei.c:3887 [inline]
> path_openat+0x2ee5/0x3830 fs/namei.c:4046
> do_filp_open+0x1fa/0x410 fs/namei.c:4073
> do_sys_openat2+0x121/0x1c0 fs/open.c:1435
> do_sys_open fs/open.c:1450 [inline]
> __do_sys_openat fs/open.c:1466 [inline]
> __se_sys_openat fs/open.c:1461 [inline]
> __x64_sys_openat+0x138/0x170 fs/open.c:1461
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> -> #4 (set->srcu){.+.+}-{0:0}:
> lock_sync+0xba/0x160 kernel/locking/lockdep.c:5916
> srcu_lock_sync include/linux/srcu.h:173 [inline]
> __synchronize_srcu+0x96/0x3a0 kernel/rcu/srcutree.c:1429
> elevator_switch+0x12b/0x640 block/elevator.c:588
> elevator_change+0x2d4/0x450 block/elevator.c:690
> elevator_set_default+0x186/0x260 block/elevator.c:766
> blk_register_queue+0x34e/0x3f0 block/blk-sysfs.c:904
> __add_disk+0x677/0xd50 block/genhd.c:528
> add_disk_fwnode+0xfc/0x480 block/genhd.c:597
> add_disk include/linux/blkdev.h:774 [inline]
> nbd_dev_add+0x717/0xae0 drivers/block/nbd.c:1973
> nbd_init+0x168/0x1f0 drivers/block/nbd.c:2680
> do_one_initcall+0x233/0x820 init/main.c:1269
> do_initcall_level+0x104/0x190 init/main.c:1331
> do_initcalls+0x59/0xa0 init/main.c:1347
> kernel_init_freeable+0x334/0x4b0 init/main.c:1579
> kernel_init+0x1d/0x1d0 init/main.c:1469
> ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>
> -> #3 (&q->elevator_lock){+.+.}-{4:4}:
> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
> __mutex_lock_common kernel/locking/mutex.c:598 [inline]
> __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
> elevator_change+0x19b/0x450 block/elevator.c:688
> elevator_set_none+0x42/0xb0 block/elevator.c:781
> blk_mq_elv_switch_none block/blk-mq.c:5023 [inline]
> __blk_mq_update_nr_hw_queues block/blk-mq.c:5066 [inline]
> blk_mq_update_nr_hw_queues+0x598/0x1aa0 block/blk-mq.c:5124
> nbd_start_device+0x17f/0xb10 drivers/block/nbd.c:1478
> nbd_genl_connect+0x135b/0x18f0 drivers/block/nbd.c:2228
> genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115
> genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
> genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
> netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
> genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
> netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
> netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
> netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
> sock_sendmsg_nosec net/socket.c:714 [inline]
> __sock_sendmsg+0x219/0x270 net/socket.c:729
> ____sys_sendmsg+0x505/0x830 net/socket.c:2614
> ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
> __sys_sendmsg net/socket.c:2700 [inline]
> __do_sys_sendmsg net/socket.c:2705 [inline]
> __se_sys_sendmsg net/socket.c:2703 [inline]
> __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> -> #2 (&q->q_usage_counter(io)#49){++++}-{0:0}:
> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
> blk_alloc_queue+0x538/0x620 block/blk-core.c:461
> blk_mq_alloc_queue block/blk-mq.c:4400 [inline]
> __blk_mq_alloc_disk+0x15c/0x340 block/blk-mq.c:4447
> nbd_dev_add+0x46c/0xae0 drivers/block/nbd.c:1943
> nbd_init+0x168/0x1f0 drivers/block/nbd.c:2680
> do_one_initcall+0x233/0x820 init/main.c:1269
> do_initcall_level+0x104/0x190 init/main.c:1331
> do_initcalls+0x59/0xa0 init/main.c:1347
> kernel_init_freeable+0x334/0x4b0 init/main.c:1579
> kernel_init+0x1d/0x1d0 init/main.c:1469
> ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>
> -> #1 (fs_reclaim){+.+.}-{0:0}:
> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
> __fs_reclaim_acquire mm/page_alloc.c:4234 [inline]
> fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4248
> might_alloc include/linux/sched/mm.h:318 [inline]
> slab_pre_alloc_hook mm/slub.c:4131 [inline]
> slab_alloc_node mm/slub.c:4209 [inline]
> kmem_cache_alloc_node_noprof+0x47/0x3c0 mm/slub.c:4281
> __alloc_skb+0x112/0x2d0 net/core/skbuff.c:659
> alloc_skb include/linux/skbuff.h:1336 [inline]
> __ip6_append_data+0x2c16/0x3f30 net/ipv6/ip6_output.c:1671
> ip6_append_data+0x1c4/0x380 net/ipv6/ip6_output.c:1860
> rawv6_sendmsg+0x127a/0x1820 net/ipv6/raw.c:911
> sock_sendmsg_nosec net/socket.c:714 [inline]
> __sock_sendmsg+0x19c/0x270 net/socket.c:729
> ____sys_sendmsg+0x505/0x830 net/socket.c:2614
> ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
> __sys_sendmsg net/socket.c:2700 [inline]
> __do_sys_sendmsg net/socket.c:2705 [inline]
> __se_sys_sendmsg net/socket.c:2703 [inline]
> __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> -> #0 (sk_lock-AF_INET6){+.+.}-{0:0}:
> check_prev_add kernel/locking/lockdep.c:3165 [inline]
> check_prevs_add kernel/locking/lockdep.c:3284 [inline]
> validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
> __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
> lock_sock_nested+0x48/0x100 net/core/sock.c:3733
> lock_sock include/net/sock.h:1667 [inline]
> inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
> nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
> nbd_send_cmd+0x11ec/0x1ba0 drivers/block/nbd.c:799
> nbd_handle_cmd drivers/block/nbd.c:1174 [inline]
> nbd_queue_rq+0xcdb/0xf10 drivers/block/nbd.c:1204
> blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
> __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
> blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
> __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
> blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
> blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
> blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
> blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
> __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
> blk_finish_plug block/blk-core.c:1247 [inline]
> __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
> __submit_bio_noacct_mq block/blk-core.c:722 [inline]
> submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
> submit_bh fs/buffer.c:2829 [inline]
> block_read_full_folio+0x599/0x830 fs/buffer.c:2447
> filemap_read_folio+0x114/0x380 mm/filemap.c:2413
> do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
> read_mapping_folio include/linux/pagemap.h:991 [inline]
> read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
> adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
> check_partition block/partitions/core.c:141 [inline]
> blk_add_partitions block/partitions/core.c:589 [inline]
> bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
> blkdev_get_whole+0x380/0x510 block/bdev.c:748
> bdev_open+0x31e/0xd30 block/bdev.c:957
> blkdev_open+0x3a8/0x510 block/fops.c:691
> do_dentry_open+0x950/0x13f0 fs/open.c:965
> vfs_open+0x3b/0x340 fs/open.c:1095
> do_open fs/namei.c:3887 [inline]
> path_openat+0x2ee5/0x3830 fs/namei.c:4046
> do_filp_open+0x1fa/0x410 fs/namei.c:4073
> do_sys_openat2+0x121/0x1c0 fs/open.c:1435
> do_sys_open fs/open.c:1450 [inline]
> __do_sys_openat fs/open.c:1466 [inline]
> __se_sys_openat fs/open.c:1461 [inline]
> __x64_sys_openat+0x138/0x170 fs/open.c:1461
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>
> other info that might help us debug this:
>
> Chain exists of:
> sk_lock-AF_INET6 --> &cmd->lock --> &nsock->tx_lock
>
> Possible unsafe locking scenario:
>
> CPU0 CPU1
> ---- ----
> lock(&nsock->tx_lock);
> lock(&cmd->lock);
> lock(&nsock->tx_lock);
> lock(sk_lock-AF_INET6);
>
> *** DEADLOCK ***
>
> 4 locks held by udevd/5878:
> #0: ffff8880250f6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
> #1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
> #1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
> #1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2358
> #2: ffff88805a2e0178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196
> #3: ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
> #3: ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_queue_rq+0xa66/0xf10 drivers/block/nbd.c:1204
>
> stack backtrace:
> CPU: 0 UID: 0 PID: 5878 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
> Call Trace:
> <TASK>
> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
> print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
> check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
> check_prev_add kernel/locking/lockdep.c:3165 [inline]
> check_prevs_add kernel/locking/lockdep.c:3284 [inline]
> validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
> __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
> lock_sock_nested+0x48/0x100 net/core/sock.c:3733
> lock_sock include/net/sock.h:1667 [inline]
> inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
> nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
> nbd_send_cmd+0x11ec/0x1ba0 drivers/block/nbd.c:799
> nbd_handle_cmd drivers/block/nbd.c:1174 [inline]
> nbd_queue_rq+0xcdb/0xf10 drivers/block/nbd.c:1204
> blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
> __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
> blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
> __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
> blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
> blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
> blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
> blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
> __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
> blk_finish_plug block/blk-core.c:1247 [inline]
> __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
> __submit_bio_noacct_mq block/blk-core.c:722 [inline]
> submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
> submit_bh fs/buffer.c:2829 [inline]
> block_read_full_folio+0x599/0x830 fs/buffer.c:2447
> filemap_read_folio+0x114/0x380 mm/filemap.c:2413
> do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
> read_mapping_folio include/linux/pagemap.h:991 [inline]
> read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
> adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
> check_partition block/partitions/core.c:141 [inline]
> blk_add_partitions block/partitions/core.c:589 [inline]
> bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
> blkdev_get_whole+0x380/0x510 block/bdev.c:748
> bdev_open+0x31e/0xd30 block/bdev.c:957
> blkdev_open+0x3a8/0x510 block/fops.c:691
> do_dentry_open+0x950/0x13f0 fs/open.c:965
> vfs_open+0x3b/0x340 fs/open.c:1095
> do_open fs/namei.c:3887 [inline]
> path_openat+0x2ee5/0x3830 fs/namei.c:4046
> do_filp_open+0x1fa/0x410 fs/namei.c:4073
> do_sys_openat2+0x121/0x1c0 fs/open.c:1435
> do_sys_open fs/open.c:1450 [inline]
> __do_sys_openat fs/open.c:1466 [inline]
> __se_sys_openat fs/open.c:1461 [inline]
> __x64_sys_openat+0x138/0x170 fs/open.c:1461
> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
> entry_SYSCALL_64_after_hwframe+0x77/0x7f
> RIP: 0033:0x7f6d8e8a7407
> Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
> RSP: 002b:00007ffc70a60620 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
> RAX: ffffffffffffffda RBX: 00007f6d8f007880 RCX: 00007f6d8e8a7407
> RDX: 00000000000a0800 RSI: 000056300ccb64f0 RDI: ffffffffffffff9c
> RBP: 000056300cc95910 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000202 R12: 000056300ccc6350
> R13: 000056300cca3190 R14: 0000000000000000 R15: 000056300ccc6350
> </TASK>
> I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 1, async page read
> I/O error, dev nbd0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 2, async page read
> I/O error, dev nbd0, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 3, async page read
> I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 0, async page read
> I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 1, async page read
> I/O error, dev nbd0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 2, async page read
> I/O error, dev nbd0, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 3, async page read
> I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 0, async page read
> I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd0, logical block 1, async page read
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd0: unable to read RDB block 0
> nbd0: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd0: unable to read RDB block 0
> nbd0: unable to read partition table
> block nbd2: Send control failed (result -89)
> block nbd2: Request send failed, requeueing
> block nbd2: Dead connection, failed to find a fallback
> block nbd2: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd2: unable to read RDB block 0
> nbd2: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd2: unable to read RDB block 0
> nbd2: unable to read partition table
> block nbd3: Send control failed (result -89)
> block nbd3: Request send failed, requeueing
> block nbd3: Dead connection, failed to find a fallback
> block nbd3: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd3: unable to read RDB block 0
> nbd3: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd3: unable to read RDB block 0
> nbd3: unable to read partition table
> block nbd4: Send control failed (result -89)
> block nbd4: Request send failed, requeueing
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd4: unable to read RDB block 0
> nbd4: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd4: unable to read RDB block 0
> nbd4: unable to read partition table
> block nbd5: Send control failed (result -89)
> block nbd5: Request send failed, requeueing
> block nbd5: Dead connection, failed to find a fallback
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd5: unable to read RDB block 0
> nbd5: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd5: unable to read RDB block 0
> nbd5: unable to read partition table
> block nbd6: Send control failed (result -89)
> block nbd6: Request send failed, requeueing
> block nbd6: Dead connection, failed to find a fallback
> block nbd6: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd6: unable to read RDB block 0
> nbd6: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd6: unable to read RDB block 0
> nbd6: unable to read partition table
> block nbd7: Send control failed (result -89)
> block nbd7: Request send failed, requeueing
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd7: unable to read RDB block 0
> nbd7: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd7: unable to read RDB block 0
> nbd7: unable to read partition table
> block nbd8: Send control failed (result -89)
> block nbd8: Request send failed, requeueing
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd8: unable to read RDB block 0
> nbd8: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd8: unable to read RDB block 0
> nbd8: unable to read partition table
> block nbd9: Send control failed (result -32)
> block nbd9: Request send failed, requeueing
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd9: unable to read RDB block 0
> nbd9: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd9: unable to read RDB block 0
> nbd9: unable to read partition table
> block nbd10: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd10: unable to read RDB block 0
> nbd10: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd10: unable to read RDB block 0
> nbd10: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd11: unable to read RDB block 0
> nbd11: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd11: unable to read RDB block 0
> nbd11: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd12: unable to read RDB block 0
> nbd12: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd12: unable to read RDB block 0
> nbd12: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd13: unable to read RDB block 0
> nbd13: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd13: unable to read RDB block 0
> nbd13: unable to read partition table
> nbd_send_cmd: 5 callbacks suppressed
> block nbd14: Send control failed (result -89)
> nbd_send_cmd: 5 callbacks suppressed
> block nbd14: Request send failed, requeueing
> block nbd14: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd14: unable to read RDB block 0
> nbd14: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd14: unable to read RDB block 0
> nbd14: unable to read partition table
> block nbd15: Send control failed (result -89)
> block nbd15: Request send failed, requeueing
> block nbd15: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd15: unable to read RDB block 0
> nbd15: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd15: unable to read RDB block 0
> nbd15: unable to read partition table
> block nbd16: Send control failed (result -89)
> block nbd16: Request send failed, requeueing
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd16: unable to read RDB block 0
> nbd16: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd16: unable to read RDB block 0
> nbd16: unable to read partition table
> block nbd17: Send control failed (result -89)
> block nbd17: Request send failed, requeueing
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd17: unable to read RDB block 0
> nbd17: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd17: unable to read RDB block 0
> nbd17: unable to read partition table
> block nbd18: Send control failed (result -89)
> block nbd18: Request send failed, requeueing
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd18: unable to read RDB block 0
> nbd18: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd18: unable to read RDB block 0
> nbd18: unable to read partition table
> block nbd19: Send control failed (result -89)
> block nbd19: Request send failed, requeueing
> block nbd19: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd19: unable to read RDB block 0
> nbd19: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd19: unable to read RDB block 0
> nbd19: unable to read partition table
> block nbd20: Send control failed (result -89)
> block nbd20: Request send failed, requeueing
> block nbd20: Dead connection, failed to find a fallback
> blk_print_req_error: 2802 callbacks suppressed
> I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> buffer_io_error: 2802 callbacks suppressed
> Buffer I/O error on dev nbd20, logical block 1, async page read
> I/O error, dev nbd20, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd20, logical block 2, async page read
> I/O error, dev nbd20, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd20, logical block 3, async page read
> I/O error, dev nbd20, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd20, logical block 0, async page read
> I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd20, logical block 1, async page read
> I/O error, dev nbd20, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd20, logical block 2, async page read
> I/O error, dev nbd20, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd20, logical block 3, async page read
> I/O error, dev nbd20, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd20, logical block 0, async page read
> I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
> Buffer I/O error on dev nbd20, logical block 1, async page read
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd20: unable to read RDB block 0
> nbd20: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd20: unable to read RDB block 0
> nbd20: unable to read partition table
> block nbd21: Send control failed (result -89)
> block nbd21: Request send failed, requeueing
> block nbd21: Dead connection, failed to find a fallback
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd21: unable to read RDB block 0
> nbd21: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd21: unable to read RDB block 0
> nbd21: unable to read partition table
> block nbd22: Send control failed (result -89)
> block nbd22: Request send failed, requeueing
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd22: unable to read RDB block 0
> nbd22: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd22: unable to read RDB block 0
> nbd22: unable to read partition table
> block nbd23: Send control failed (result -89)
> block nbd23: Request send failed, requeueing
> block nbd23: Dead connection, failed to find a fallback
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd23: unable to read RDB block 0
> nbd23: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd23: unable to read RDB block 0
> nbd23: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd24: unable to read RDB block 0
> nbd24: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd24: unable to read RDB block 0
> nbd24: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd25: unable to read RDB block 0
> nbd25: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd25: unable to read RDB block 0
> nbd25: unable to read partition table
> block nbd26: Dead connection, failed to find a fallback
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd26: unable to read RDB block 0
> nbd26: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd26: unable to read RDB block 0
> nbd26: unable to read partition table
> block nbd27: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd27: unable to read RDB block 0
> nbd27: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd27: unable to read RDB block 0
> nbd27: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd28: unable to read RDB block 0
> nbd28: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd28: unable to read RDB block 0
> nbd28: unable to read partition table
> block nbd29: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd29: unable to read RDB block 0
> nbd29: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd29: unable to read RDB block 0
> nbd29: unable to read partition table
> block nbd30: shutting down sockets
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd30: unable to read RDB block 0
> nbd30: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd30: unable to read RDB block 0
> nbd30: unable to read partition table
> ldm_validate_partition_table(): Disk read failed.
> Dev nbd31: unable to read RDB block 0
> nbd31: unable to read partition table
>
>
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
>
> syzbot will keep track of this issue. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>
> If the report is already addressed, let syzbot know by replying with:
> #syz fix: exact-commit-title
>
> If you want syzbot to run the reproducer, reply with:
> #syz test: git://repo/address.git branch-or-commit-hash
> If you attach or paste a git patch, syzbot will apply it before testing.
>
> If you want to overwrite report's subsystems, reply with:
> #syz set subsystems: new-subsystem
> (See the list of subsystem names on the web dashboard)
>
> If the report is a duplicate of another one, reply with:
> #syz dup: exact-subject-of-another-report
>
> If you want to undo deduplication, reply with:
> #syz undup
Question to NBD maintainers.
What socket types are supposed to be supported by NBD ?
I was thinking adding a list of supported ones, assuming TCP and
stream unix are the only ones:
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 6463d0e8d0ce..87b0b78249da 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -1217,6 +1217,14 @@ static struct socket *nbd_get_socket(struct
nbd_device *nbd, unsigned long fd,
if (!sock)
return NULL;
+ if (!sk_is_tcp(sock->sk) &&
+ !sk_is_stream_unix(sock->sk)) {
+ dev_err(disk_to_dev(nbd->disk), "Unsupported socket:
should be TCP or UNIX.\n");
+ *err = -EINVAL;
+ sockfd_put(sock);
+ return NULL;
+ }
+
if (sock->ops->shutdown == sock_no_shutdown) {
dev_err(disk_to_dev(nbd->disk), "Unsupported socket:
shutdown callout must be supported.\n");
*err = -EINVAL;
^ permalink raw reply related [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-05 20:03 ` Eric Dumazet
@ 2025-09-06 9:16 ` Eric Dumazet
2025-09-08 8:52 ` Yu Kuai
2025-09-08 14:26 ` Jens Axboe
1 sibling, 1 reply; 11+ messages in thread
From: Eric Dumazet @ 2025-09-06 9:16 UTC (permalink / raw)
To: syzbot, Josef Bacik, Jens Axboe
Cc: davem, dsahern, horms, kuba, linux-block, linux-kernel, ming.lei,
netdev, pabeni, syzkaller-bugs, thomas.hellstrom
On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@google.com> wrote:
>
> On Fri, Sep 5, 2025 at 1:00 PM syzbot
> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
Note to NBD maintainers : I held about 20 syzbot reports all pointing
to NBD accepting various sockets, I can release them if needed, if you prefer
to triage them.
>
> Question to NBD maintainers.
>
> What socket types are supposed to be supported by NBD ?
>
> I was thinking adding a list of supported ones, assuming TCP and
> stream unix are the only ones:
>
> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> index 6463d0e8d0ce..87b0b78249da 100644
> --- a/drivers/block/nbd.c
> +++ b/drivers/block/nbd.c
> @@ -1217,6 +1217,14 @@ static struct socket *nbd_get_socket(struct
> nbd_device *nbd, unsigned long fd,
> if (!sock)
> return NULL;
>
> + if (!sk_is_tcp(sock->sk) &&
> + !sk_is_stream_unix(sock->sk)) {
> + dev_err(disk_to_dev(nbd->disk), "Unsupported socket:
> should be TCP or UNIX.\n");
> + *err = -EINVAL;
> + sockfd_put(sock);
> + return NULL;
> + }
> +
> if (sock->ops->shutdown == sock_no_shutdown) {
> dev_err(disk_to_dev(nbd->disk), "Unsupported socket:
> shutdown callout must be supported.\n");
> *err = -EINVAL;
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-06 9:16 ` Eric Dumazet
@ 2025-09-08 8:52 ` Yu Kuai
2025-09-08 9:07 ` Eric Dumazet
0 siblings, 1 reply; 11+ messages in thread
From: Yu Kuai @ 2025-09-08 8:52 UTC (permalink / raw)
To: Eric Dumazet, syzbot, Josef Bacik, Jens Axboe
Cc: davem, dsahern, horms, kuba, linux-block, linux-kernel, ming.lei,
netdev, pabeni, syzkaller-bugs, thomas.hellstrom, yukuai (C)
Hi,
在 2025/09/06 17:16, Eric Dumazet 写道:
> On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@google.com> wrote:
>>
>> On Fri, Sep 5, 2025 at 1:00 PM syzbot
>> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
>
> Note to NBD maintainers : I held about 20 syzbot reports all pointing
> to NBD accepting various sockets, I can release them if needed, if you prefer
> to triage them.
>
I'm not NBD maintainer, just trying to understand the deadlock first.
Is this deadlock only possible for some sepecific socket types? Take
a look at the report here:
Usually issue IO will require the order:
q_usage_counter -> cmd lock -> tx lock -> sk lock
Hence the condition is that if the sock_sendmsg() will hold sk lock to
allocate new memory, and can trigger fs reclaim, and finally issue new
IO to this nbd?
Thanks,
Kuai
>>
>> Question to NBD maintainers.
>>
>> What socket types are supposed to be supported by NBD ?
>>
>> I was thinking adding a list of supported ones, assuming TCP and
>> stream unix are the only ones:
>>
>> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
>> index 6463d0e8d0ce..87b0b78249da 100644
>> --- a/drivers/block/nbd.c
>> +++ b/drivers/block/nbd.c
>> @@ -1217,6 +1217,14 @@ static struct socket *nbd_get_socket(struct
>> nbd_device *nbd, unsigned long fd,
>> if (!sock)
>> return NULL;
>>
>> + if (!sk_is_tcp(sock->sk) &&
>> + !sk_is_stream_unix(sock->sk)) {
>> + dev_err(disk_to_dev(nbd->disk), "Unsupported socket:
>> should be TCP or UNIX.\n");
>> + *err = -EINVAL;
>> + sockfd_put(sock);
>> + return NULL;
>> + }
>> +
>> if (sock->ops->shutdown == sock_no_shutdown) {
>> dev_err(disk_to_dev(nbd->disk), "Unsupported socket:
>> shutdown callout must be supported.\n");
>> *err = -EINVAL;
>
> .
>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-08 8:52 ` Yu Kuai
@ 2025-09-08 9:07 ` Eric Dumazet
2025-09-08 9:34 ` Yu Kuai
2025-09-08 13:03 ` Hillf Danton
0 siblings, 2 replies; 11+ messages in thread
From: Eric Dumazet @ 2025-09-08 9:07 UTC (permalink / raw)
To: Yu Kuai
Cc: syzbot, Josef Bacik, Jens Axboe, davem, dsahern, horms, kuba,
linux-block, linux-kernel, ming.lei, netdev, pabeni,
syzkaller-bugs, thomas.hellstrom, yukuai (C)
On Mon, Sep 8, 2025 at 1:52 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>
> Hi,
>
> 在 2025/09/06 17:16, Eric Dumazet 写道:
> > On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@google.com> wrote:
> >>
> >> On Fri, Sep 5, 2025 at 1:00 PM syzbot
> >> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
> >
> > Note to NBD maintainers : I held about 20 syzbot reports all pointing
> > to NBD accepting various sockets, I can release them if needed, if you prefer
> > to triage them.
> >
> I'm not NBD maintainer, just trying to understand the deadlock first.
>
> Is this deadlock only possible for some sepecific socket types? Take
> a look at the report here:
>
> Usually issue IO will require the order:
>
> q_usage_counter -> cmd lock -> tx lock -> sk lock
>
I have not seen the deadlock being reported with normal TCP sockets.
NBD sets sk->sk_allocation to GFP_NOIO | __GFP_MEMALLOC;
from __sock_xmit(), and TCP seems to respect this.
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-08 9:07 ` Eric Dumazet
@ 2025-09-08 9:34 ` Yu Kuai
2025-09-08 9:40 ` Eric Dumazet
2025-09-08 13:03 ` Hillf Danton
1 sibling, 1 reply; 11+ messages in thread
From: Yu Kuai @ 2025-09-08 9:34 UTC (permalink / raw)
To: Eric Dumazet, Yu Kuai
Cc: syzbot, Josef Bacik, Jens Axboe, davem, dsahern, horms, kuba,
linux-block, linux-kernel, ming.lei, netdev, pabeni,
syzkaller-bugs, thomas.hellstrom, yukuai (C)
Hi,
在 2025/09/08 17:07, Eric Dumazet 写道:
> On Mon, Sep 8, 2025 at 1:52 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>>
>> Hi,
>>
>> 在 2025/09/06 17:16, Eric Dumazet 写道:
>>> On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@google.com> wrote:
>>>>
>>>> On Fri, Sep 5, 2025 at 1:00 PM syzbot
>>>> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
>>>
>>> Note to NBD maintainers : I held about 20 syzbot reports all pointing
>>> to NBD accepting various sockets, I can release them if needed, if you prefer
>>> to triage them.
>>>
>> I'm not NBD maintainer, just trying to understand the deadlock first.
>>
>> Is this deadlock only possible for some sepecific socket types? Take
>> a look at the report here:
>>
>> Usually issue IO will require the order:
>>
>> q_usage_counter -> cmd lock -> tx lock -> sk lock
>>
>
> I have not seen the deadlock being reported with normal TCP sockets.
>
> NBD sets sk->sk_allocation to GFP_NOIO | __GFP_MEMALLOC;
> from __sock_xmit(), and TCP seems to respect this.
> .
>
What aboud iscsi and nvme-tcp? and probably other drivers, where
sk_allocation is GFP_ATOMIC, do they have similar problem?
Thanks,
Kuai
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-08 9:34 ` Yu Kuai
@ 2025-09-08 9:40 ` Eric Dumazet
2025-09-09 9:16 ` Yu Kuai
0 siblings, 1 reply; 11+ messages in thread
From: Eric Dumazet @ 2025-09-08 9:40 UTC (permalink / raw)
To: Yu Kuai
Cc: syzbot, Josef Bacik, Jens Axboe, davem, dsahern, horms, kuba,
linux-block, linux-kernel, ming.lei, netdev, pabeni,
syzkaller-bugs, thomas.hellstrom, yukuai (C)
On Mon, Sep 8, 2025 at 2:34 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>
> Hi,
>
> 在 2025/09/08 17:07, Eric Dumazet 写道:
> > On Mon, Sep 8, 2025 at 1:52 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
> >>
> >> Hi,
> >>
> >> 在 2025/09/06 17:16, Eric Dumazet 写道:
> >>> On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@google.com> wrote:
> >>>>
> >>>> On Fri, Sep 5, 2025 at 1:00 PM syzbot
> >>>> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
> >>>
> >>> Note to NBD maintainers : I held about 20 syzbot reports all pointing
> >>> to NBD accepting various sockets, I can release them if needed, if you prefer
> >>> to triage them.
> >>>
> >> I'm not NBD maintainer, just trying to understand the deadlock first.
> >>
> >> Is this deadlock only possible for some sepecific socket types? Take
> >> a look at the report here:
> >>
> >> Usually issue IO will require the order:
> >>
> >> q_usage_counter -> cmd lock -> tx lock -> sk lock
> >>
> >
> > I have not seen the deadlock being reported with normal TCP sockets.
> >
> > NBD sets sk->sk_allocation to GFP_NOIO | __GFP_MEMALLOC;
> > from __sock_xmit(), and TCP seems to respect this.
> > .
> >
>
> What aboud iscsi and nvme-tcp? and probably other drivers, where
> sk_allocation is GFP_ATOMIC, do they have similar problem?
>
AFAIK after this fix, iscsi was fine.
commit f4f82c52a0ead5ab363d207d06f81b967d09ffb8
Author: Eric Dumazet <edumazet@google.com>
Date: Fri Sep 15 17:11:11 2023 +0000
scsi: iscsi_tcp: restrict to TCP sockets
Nothing prevents iscsi_sw_tcp_conn_bind() to receive file descriptor
pointing to non TCP socket (af_unix for example).
Return -EINVAL if this is attempted, instead of crashing the kernel.
Fixes: 7ba247138907 ("[SCSI] open-iscsi/linux-iscsi-5 Initiator:
Initiator code")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lee Duncan <lduncan@suse.com>
Cc: Chris Leech <cleech@redhat.com>
Cc: Mike Christie <michael.christie@oracle.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: open-iscsi@googlegroups.com
Cc: linux-scsi@vger.kernel.org
Reviewed-by: Mike Christie <michael.christie@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-08 9:07 ` Eric Dumazet
2025-09-08 9:34 ` Yu Kuai
@ 2025-09-08 13:03 ` Hillf Danton
1 sibling, 0 replies; 11+ messages in thread
From: Hillf Danton @ 2025-09-08 13:03 UTC (permalink / raw)
To: Eric Dumazet, Yu Kuai
Cc: syzbot, Josef Bacik, Jens Axboe, linux-block, linux-kernel,
netdev, syzkaller-bugs, thomas.hellstrom
在 2025/09/08 17:07, Eric Dumazet 写道:
> On Mon, Sep 8, 2025 at 1:52 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>> 在 2025/09/06 17:16, Eric Dumazet 写道:
>>> On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@google.com> wrote:
>>>> On Fri, Sep 5, 2025 at 1:00 PM syzbot
>>>> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
>>>
>>> Note to NBD maintainers : I held about 20 syzbot reports all pointing
>>> to NBD accepting various sockets, I can release them if needed, if you prefer
>>> to triage them.
>>>
>> I'm not NBD maintainer, just trying to understand the deadlock first.
>>
>> Is this deadlock only possible for some sepecific socket types? Take
>> a look at the report here:
>>
>> Usually issue IO will require the order:
>>
>> q_usage_counter -> cmd lock -> tx lock -> sk lock
>>
>
> I have not seen the deadlock being reported with normal TCP sockets.
>
> NBD sets sk->sk_allocation to GFP_NOIO | __GFP_MEMALLOC;
> from __sock_xmit(), and TCP seems to respect this.
>
Only if ffa1e7ada45 is missed, given the __correct__ locking order
enforced in ffa1e7ada45 ("block: Make request_queue lockdep splats
show up earlier"), GFP_NOIO does not help to cure any case that
reverses that order, while __GFP_MEMALLOC looks like a paperover,
at least because __GFP_MEMALLOC does not match lock_sock().
-> #0 (sk_lock-AF_INET6){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
__lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
lock_sock_nested+0x48/0x100 net/core/sock.c:3733
lock_sock include/net/sock.h:1667 [inline]
inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
nbd_send_cmd+0x11ec/0x1ba0 drivers/block/nbd.c:799
nbd_handle_cmd drivers/block/nbd.c:1174 [inline]
nbd_queue_rq+0xcdb/0xf10 drivers/block/nbd.c:1204
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-05 20:03 ` Eric Dumazet
2025-09-06 9:16 ` Eric Dumazet
@ 2025-09-08 14:26 ` Jens Axboe
1 sibling, 0 replies; 11+ messages in thread
From: Jens Axboe @ 2025-09-08 14:26 UTC (permalink / raw)
To: Eric Dumazet, syzbot, Josef Bacik
Cc: davem, dsahern, horms, kuba, linux-block, linux-kernel, ming.lei,
netdev, pabeni, syzkaller-bugs, thomas.hellstrom
On 9/5/25 2:03 PM, Eric Dumazet wrote:
> On Fri, Sep 5, 2025 at 1:00 PM syzbot
> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
>>
>> Hello,
>>
>> syzbot found the following issue on:
>>
>> HEAD commit: 788bc43d8330 Merge branch 'microchip-lan865x-fix-probing-i..
>> git tree: net
>> console output: https://syzkaller.appspot.com/x/log.txt?x=10fc4e34580000
>> kernel config: https://syzkaller.appspot.com/x/.config?x=9c302bcfb26a48af
>> dashboard link: https://syzkaller.appspot.com/bug?extid=e1cd6bd8493060bd701d
>> compiler: Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8
>> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=136c41f0580000
>> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13bac242580000
>>
>> Downloadable assets:
>> disk image: https://storage.googleapis.com/syzbot-assets/c958eee3370d/disk-788bc43d.raw.xz
>> vmlinux: https://storage.googleapis.com/syzbot-assets/615040093399/vmlinux-788bc43d.xz
>> kernel image: https://storage.googleapis.com/syzbot-assets/91377e9f5c93/bzImage-788bc43d.xz
>>
>> The issue was bisected to:
>>
>> commit ffa1e7ada456087c2402b37cd6b2863ced29aff0
>> Author: Thomas Hellström <thomas.hellstrom@linux.intel.com>
>> Date: Tue Mar 18 09:55:48 2025 +0000
>>
>> block: Make request_queue lockdep splats show up earlier
>>
>> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1263c1f0580000
>> final oops: https://syzkaller.appspot.com/x/report.txt?x=1163c1f0580000
>> console output: https://syzkaller.appspot.com/x/log.txt?x=1663c1f0580000
>>
>> IMPORTANT: if you fix the issue, please add the following tag to the commit:
>> Reported-by: syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com
>> Fixes: ffa1e7ada456 ("block: Make request_queue lockdep splats show up earlier")
>>
>> block nbd0: Send control failed (result -89)
>> block nbd0: Request send failed, requeueing
>> ======================================================
>> WARNING: possible circular locking dependency detected
>> syzkaller #0 Not tainted
>> ------------------------------------------------------
>> udevd/5878 is trying to acquire lock:
>> ffff88807ba3eed8 (sk_lock-AF_INET6){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1667 [inline]
>> ffff88807ba3eed8 (sk_lock-AF_INET6){+.+.}-{0:0}, at: inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
>>
>> but task is already holding lock:
>> ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
>> ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_queue_rq+0xa66/0xf10 drivers/block/nbd.c:1204
>>
>> which lock already depends on the new lock.
>>
>>
>> the existing dependency chain (in reverse order) is:
>>
>> -> #6 (&nsock->tx_lock){+.+.}-{4:4}:
>> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
>> __mutex_lock_common kernel/locking/mutex.c:598 [inline]
>> __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
>> nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
>> nbd_queue_rq+0x257/0xf10 drivers/block/nbd.c:1204
>> blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
>> __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
>> blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
>> __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
>> blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
>> blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
>> blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
>> blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
>> __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
>> blk_finish_plug block/blk-core.c:1247 [inline]
>> __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
>> __submit_bio_noacct_mq block/blk-core.c:722 [inline]
>> submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
>> submit_bh fs/buffer.c:2829 [inline]
>> block_read_full_folio+0x599/0x830 fs/buffer.c:2447
>> filemap_read_folio+0x114/0x380 mm/filemap.c:2413
>> do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
>> read_mapping_folio include/linux/pagemap.h:991 [inline]
>> read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
>> adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
>> check_partition block/partitions/core.c:141 [inline]
>> blk_add_partitions block/partitions/core.c:589 [inline]
>> bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
>> blkdev_get_whole+0x380/0x510 block/bdev.c:748
>> bdev_open+0x31e/0xd30 block/bdev.c:957
>> blkdev_open+0x3a8/0x510 block/fops.c:691
>> do_dentry_open+0x950/0x13f0 fs/open.c:965
>> vfs_open+0x3b/0x340 fs/open.c:1095
>> do_open fs/namei.c:3887 [inline]
>> path_openat+0x2ee5/0x3830 fs/namei.c:4046
>> do_filp_open+0x1fa/0x410 fs/namei.c:4073
>> do_sys_openat2+0x121/0x1c0 fs/open.c:1435
>> do_sys_open fs/open.c:1450 [inline]
>> __do_sys_openat fs/open.c:1466 [inline]
>> __se_sys_openat fs/open.c:1461 [inline]
>> __x64_sys_openat+0x138/0x170 fs/open.c:1461
>> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>
>> -> #5 (&cmd->lock){+.+.}-{4:4}:
>> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
>> __mutex_lock_common kernel/locking/mutex.c:598 [inline]
>> __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
>> nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196
>> blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
>> __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
>> blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
>> __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
>> blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
>> blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
>> blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
>> blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
>> __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
>> blk_finish_plug block/blk-core.c:1247 [inline]
>> __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
>> __submit_bio_noacct_mq block/blk-core.c:722 [inline]
>> submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
>> submit_bh fs/buffer.c:2829 [inline]
>> block_read_full_folio+0x599/0x830 fs/buffer.c:2447
>> filemap_read_folio+0x114/0x380 mm/filemap.c:2413
>> do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
>> read_mapping_folio include/linux/pagemap.h:991 [inline]
>> read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
>> adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
>> check_partition block/partitions/core.c:141 [inline]
>> blk_add_partitions block/partitions/core.c:589 [inline]
>> bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
>> blkdev_get_whole+0x380/0x510 block/bdev.c:748
>> bdev_open+0x31e/0xd30 block/bdev.c:957
>> blkdev_open+0x3a8/0x510 block/fops.c:691
>> do_dentry_open+0x950/0x13f0 fs/open.c:965
>> vfs_open+0x3b/0x340 fs/open.c:1095
>> do_open fs/namei.c:3887 [inline]
>> path_openat+0x2ee5/0x3830 fs/namei.c:4046
>> do_filp_open+0x1fa/0x410 fs/namei.c:4073
>> do_sys_openat2+0x121/0x1c0 fs/open.c:1435
>> do_sys_open fs/open.c:1450 [inline]
>> __do_sys_openat fs/open.c:1466 [inline]
>> __se_sys_openat fs/open.c:1461 [inline]
>> __x64_sys_openat+0x138/0x170 fs/open.c:1461
>> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>
>> -> #4 (set->srcu){.+.+}-{0:0}:
>> lock_sync+0xba/0x160 kernel/locking/lockdep.c:5916
>> srcu_lock_sync include/linux/srcu.h:173 [inline]
>> __synchronize_srcu+0x96/0x3a0 kernel/rcu/srcutree.c:1429
>> elevator_switch+0x12b/0x640 block/elevator.c:588
>> elevator_change+0x2d4/0x450 block/elevator.c:690
>> elevator_set_default+0x186/0x260 block/elevator.c:766
>> blk_register_queue+0x34e/0x3f0 block/blk-sysfs.c:904
>> __add_disk+0x677/0xd50 block/genhd.c:528
>> add_disk_fwnode+0xfc/0x480 block/genhd.c:597
>> add_disk include/linux/blkdev.h:774 [inline]
>> nbd_dev_add+0x717/0xae0 drivers/block/nbd.c:1973
>> nbd_init+0x168/0x1f0 drivers/block/nbd.c:2680
>> do_one_initcall+0x233/0x820 init/main.c:1269
>> do_initcall_level+0x104/0x190 init/main.c:1331
>> do_initcalls+0x59/0xa0 init/main.c:1347
>> kernel_init_freeable+0x334/0x4b0 init/main.c:1579
>> kernel_init+0x1d/0x1d0 init/main.c:1469
>> ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
>> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>>
>> -> #3 (&q->elevator_lock){+.+.}-{4:4}:
>> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
>> __mutex_lock_common kernel/locking/mutex.c:598 [inline]
>> __mutex_lock+0x187/0x1350 kernel/locking/mutex.c:760
>> elevator_change+0x19b/0x450 block/elevator.c:688
>> elevator_set_none+0x42/0xb0 block/elevator.c:781
>> blk_mq_elv_switch_none block/blk-mq.c:5023 [inline]
>> __blk_mq_update_nr_hw_queues block/blk-mq.c:5066 [inline]
>> blk_mq_update_nr_hw_queues+0x598/0x1aa0 block/blk-mq.c:5124
>> nbd_start_device+0x17f/0xb10 drivers/block/nbd.c:1478
>> nbd_genl_connect+0x135b/0x18f0 drivers/block/nbd.c:2228
>> genl_family_rcv_msg_doit+0x212/0x300 net/netlink/genetlink.c:1115
>> genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline]
>> genl_rcv_msg+0x60e/0x790 net/netlink/genetlink.c:1210
>> netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
>> genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219
>> netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
>> netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1346
>> netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
>> sock_sendmsg_nosec net/socket.c:714 [inline]
>> __sock_sendmsg+0x219/0x270 net/socket.c:729
>> ____sys_sendmsg+0x505/0x830 net/socket.c:2614
>> ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
>> __sys_sendmsg net/socket.c:2700 [inline]
>> __do_sys_sendmsg net/socket.c:2705 [inline]
>> __se_sys_sendmsg net/socket.c:2703 [inline]
>> __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
>> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>
>> -> #2 (&q->q_usage_counter(io)#49){++++}-{0:0}:
>> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
>> blk_alloc_queue+0x538/0x620 block/blk-core.c:461
>> blk_mq_alloc_queue block/blk-mq.c:4400 [inline]
>> __blk_mq_alloc_disk+0x15c/0x340 block/blk-mq.c:4447
>> nbd_dev_add+0x46c/0xae0 drivers/block/nbd.c:1943
>> nbd_init+0x168/0x1f0 drivers/block/nbd.c:2680
>> do_one_initcall+0x233/0x820 init/main.c:1269
>> do_initcall_level+0x104/0x190 init/main.c:1331
>> do_initcalls+0x59/0xa0 init/main.c:1347
>> kernel_init_freeable+0x334/0x4b0 init/main.c:1579
>> kernel_init+0x1d/0x1d0 init/main.c:1469
>> ret_from_fork+0x3f9/0x770 arch/x86/kernel/process.c:148
>> ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
>>
>> -> #1 (fs_reclaim){+.+.}-{0:0}:
>> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
>> __fs_reclaim_acquire mm/page_alloc.c:4234 [inline]
>> fs_reclaim_acquire+0x72/0x100 mm/page_alloc.c:4248
>> might_alloc include/linux/sched/mm.h:318 [inline]
>> slab_pre_alloc_hook mm/slub.c:4131 [inline]
>> slab_alloc_node mm/slub.c:4209 [inline]
>> kmem_cache_alloc_node_noprof+0x47/0x3c0 mm/slub.c:4281
>> __alloc_skb+0x112/0x2d0 net/core/skbuff.c:659
>> alloc_skb include/linux/skbuff.h:1336 [inline]
>> __ip6_append_data+0x2c16/0x3f30 net/ipv6/ip6_output.c:1671
>> ip6_append_data+0x1c4/0x380 net/ipv6/ip6_output.c:1860
>> rawv6_sendmsg+0x127a/0x1820 net/ipv6/raw.c:911
>> sock_sendmsg_nosec net/socket.c:714 [inline]
>> __sock_sendmsg+0x19c/0x270 net/socket.c:729
>> ____sys_sendmsg+0x505/0x830 net/socket.c:2614
>> ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2668
>> __sys_sendmsg net/socket.c:2700 [inline]
>> __do_sys_sendmsg net/socket.c:2705 [inline]
>> __se_sys_sendmsg net/socket.c:2703 [inline]
>> __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2703
>> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>
>> -> #0 (sk_lock-AF_INET6){+.+.}-{0:0}:
>> check_prev_add kernel/locking/lockdep.c:3165 [inline]
>> check_prevs_add kernel/locking/lockdep.c:3284 [inline]
>> validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
>> __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
>> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
>> lock_sock_nested+0x48/0x100 net/core/sock.c:3733
>> lock_sock include/net/sock.h:1667 [inline]
>> inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
>> nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
>> nbd_send_cmd+0x11ec/0x1ba0 drivers/block/nbd.c:799
>> nbd_handle_cmd drivers/block/nbd.c:1174 [inline]
>> nbd_queue_rq+0xcdb/0xf10 drivers/block/nbd.c:1204
>> blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
>> __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
>> blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
>> __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
>> blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
>> blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
>> blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
>> blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
>> __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
>> blk_finish_plug block/blk-core.c:1247 [inline]
>> __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
>> __submit_bio_noacct_mq block/blk-core.c:722 [inline]
>> submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
>> submit_bh fs/buffer.c:2829 [inline]
>> block_read_full_folio+0x599/0x830 fs/buffer.c:2447
>> filemap_read_folio+0x114/0x380 mm/filemap.c:2413
>> do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
>> read_mapping_folio include/linux/pagemap.h:991 [inline]
>> read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
>> adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
>> check_partition block/partitions/core.c:141 [inline]
>> blk_add_partitions block/partitions/core.c:589 [inline]
>> bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
>> blkdev_get_whole+0x380/0x510 block/bdev.c:748
>> bdev_open+0x31e/0xd30 block/bdev.c:957
>> blkdev_open+0x3a8/0x510 block/fops.c:691
>> do_dentry_open+0x950/0x13f0 fs/open.c:965
>> vfs_open+0x3b/0x340 fs/open.c:1095
>> do_open fs/namei.c:3887 [inline]
>> path_openat+0x2ee5/0x3830 fs/namei.c:4046
>> do_filp_open+0x1fa/0x410 fs/namei.c:4073
>> do_sys_openat2+0x121/0x1c0 fs/open.c:1435
>> do_sys_open fs/open.c:1450 [inline]
>> __do_sys_openat fs/open.c:1466 [inline]
>> __se_sys_openat fs/open.c:1461 [inline]
>> __x64_sys_openat+0x138/0x170 fs/open.c:1461
>> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>>
>> other info that might help us debug this:
>>
>> Chain exists of:
>> sk_lock-AF_INET6 --> &cmd->lock --> &nsock->tx_lock
>>
>> Possible unsafe locking scenario:
>>
>> CPU0 CPU1
>> ---- ----
>> lock(&nsock->tx_lock);
>> lock(&cmd->lock);
>> lock(&nsock->tx_lock);
>> lock(sk_lock-AF_INET6);
>>
>> *** DEADLOCK ***
>>
>> 4 locks held by udevd/5878:
>> #0: ffff8880250f6358 (&disk->open_mutex){+.+.}-{4:4}, at: bdev_open+0xe0/0xd30 block/bdev.c:945
>> #1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:161 [inline]
>> #1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:253 [inline]
>> #1: ffff888142bf5f10 (set->srcu){.+.+}-{0:0}, at: blk_mq_run_hw_queue+0x31f/0x4f0 block/blk-mq.c:2358
>> #2: ffff88805a2e0178 (&cmd->lock){+.+.}-{4:4}, at: nbd_queue_rq+0xc8/0xf10 drivers/block/nbd.c:1196
>> #3: ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_handle_cmd drivers/block/nbd.c:1140 [inline]
>> #3: ffff888074e3b470 (&nsock->tx_lock){+.+.}-{4:4}, at: nbd_queue_rq+0xa66/0xf10 drivers/block/nbd.c:1204
>>
>> stack backtrace:
>> CPU: 0 UID: 0 PID: 5878 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
>> Call Trace:
>> <TASK>
>> dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
>> print_circular_bug+0x2ee/0x310 kernel/locking/lockdep.c:2043
>> check_noncircular+0x134/0x160 kernel/locking/lockdep.c:2175
>> check_prev_add kernel/locking/lockdep.c:3165 [inline]
>> check_prevs_add kernel/locking/lockdep.c:3284 [inline]
>> validate_chain+0xb9b/0x2140 kernel/locking/lockdep.c:3908
>> __lock_acquire+0xab9/0xd20 kernel/locking/lockdep.c:5237
>> lock_acquire+0x120/0x360 kernel/locking/lockdep.c:5868
>> lock_sock_nested+0x48/0x100 net/core/sock.c:3733
>> lock_sock include/net/sock.h:1667 [inline]
>> inet_shutdown+0x6a/0x390 net/ipv4/af_inet.c:905
>> nbd_mark_nsock_dead+0x2e9/0x560 drivers/block/nbd.c:318
>> nbd_send_cmd+0x11ec/0x1ba0 drivers/block/nbd.c:799
>> nbd_handle_cmd drivers/block/nbd.c:1174 [inline]
>> nbd_queue_rq+0xcdb/0xf10 drivers/block/nbd.c:1204
>> blk_mq_dispatch_rq_list+0x4c0/0x1900 block/blk-mq.c:2120
>> __blk_mq_do_dispatch_sched block/blk-mq-sched.c:168 [inline]
>> blk_mq_do_dispatch_sched block/blk-mq-sched.c:182 [inline]
>> __blk_mq_sched_dispatch_requests+0xda4/0x1570 block/blk-mq-sched.c:307
>> blk_mq_sched_dispatch_requests+0xd7/0x190 block/blk-mq-sched.c:329
>> blk_mq_run_hw_queue+0x348/0x4f0 block/blk-mq.c:2358
>> blk_mq_dispatch_list+0xd0c/0xe00 include/linux/spinlock.h:-1
>> blk_mq_flush_plug_list+0x469/0x550 block/blk-mq.c:2967
>> __blk_flush_plug+0x3d3/0x4b0 block/blk-core.c:1220
>> blk_finish_plug block/blk-core.c:1247 [inline]
>> __submit_bio+0x2d3/0x5a0 block/blk-core.c:649
>> __submit_bio_noacct_mq block/blk-core.c:722 [inline]
>> submit_bio_noacct_nocheck+0x4ab/0xb50 block/blk-core.c:751
>> submit_bh fs/buffer.c:2829 [inline]
>> block_read_full_folio+0x599/0x830 fs/buffer.c:2447
>> filemap_read_folio+0x114/0x380 mm/filemap.c:2413
>> do_read_cache_folio+0x350/0x590 mm/filemap.c:3957
>> read_mapping_folio include/linux/pagemap.h:991 [inline]
>> read_part_sector+0xb6/0x2b0 block/partitions/core.c:722
>> adfspart_check_ICS+0xa4/0xa50 block/partitions/acorn.c:360
>> check_partition block/partitions/core.c:141 [inline]
>> blk_add_partitions block/partitions/core.c:589 [inline]
>> bdev_disk_changed+0x75f/0x14b0 block/partitions/core.c:693
>> blkdev_get_whole+0x380/0x510 block/bdev.c:748
>> bdev_open+0x31e/0xd30 block/bdev.c:957
>> blkdev_open+0x3a8/0x510 block/fops.c:691
>> do_dentry_open+0x950/0x13f0 fs/open.c:965
>> vfs_open+0x3b/0x340 fs/open.c:1095
>> do_open fs/namei.c:3887 [inline]
>> path_openat+0x2ee5/0x3830 fs/namei.c:4046
>> do_filp_open+0x1fa/0x410 fs/namei.c:4073
>> do_sys_openat2+0x121/0x1c0 fs/open.c:1435
>> do_sys_open fs/open.c:1450 [inline]
>> __do_sys_openat fs/open.c:1466 [inline]
>> __se_sys_openat fs/open.c:1461 [inline]
>> __x64_sys_openat+0x138/0x170 fs/open.c:1461
>> do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
>> do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
>> entry_SYSCALL_64_after_hwframe+0x77/0x7f
>> RIP: 0033:0x7f6d8e8a7407
>> Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
>> RSP: 002b:00007ffc70a60620 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
>> RAX: ffffffffffffffda RBX: 00007f6d8f007880 RCX: 00007f6d8e8a7407
>> RDX: 00000000000a0800 RSI: 000056300ccb64f0 RDI: ffffffffffffff9c
>> RBP: 000056300cc95910 R08: 0000000000000000 R09: 0000000000000000
>> R10: 0000000000000000 R11: 0000000000000202 R12: 000056300ccc6350
>> R13: 000056300cca3190 R14: 0000000000000000 R15: 000056300ccc6350
>> </TASK>
>> I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 1, async page read
>> I/O error, dev nbd0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 2, async page read
>> I/O error, dev nbd0, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 3, async page read
>> I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 0, async page read
>> I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 1, async page read
>> I/O error, dev nbd0, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 2, async page read
>> I/O error, dev nbd0, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 3, async page read
>> I/O error, dev nbd0, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 0, async page read
>> I/O error, dev nbd0, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd0, logical block 1, async page read
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd0: unable to read RDB block 0
>> nbd0: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd0: unable to read RDB block 0
>> nbd0: unable to read partition table
>> block nbd2: Send control failed (result -89)
>> block nbd2: Request send failed, requeueing
>> block nbd2: Dead connection, failed to find a fallback
>> block nbd2: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd2: unable to read RDB block 0
>> nbd2: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd2: unable to read RDB block 0
>> nbd2: unable to read partition table
>> block nbd3: Send control failed (result -89)
>> block nbd3: Request send failed, requeueing
>> block nbd3: Dead connection, failed to find a fallback
>> block nbd3: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd3: unable to read RDB block 0
>> nbd3: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd3: unable to read RDB block 0
>> nbd3: unable to read partition table
>> block nbd4: Send control failed (result -89)
>> block nbd4: Request send failed, requeueing
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd4: unable to read RDB block 0
>> nbd4: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd4: unable to read RDB block 0
>> nbd4: unable to read partition table
>> block nbd5: Send control failed (result -89)
>> block nbd5: Request send failed, requeueing
>> block nbd5: Dead connection, failed to find a fallback
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd5: unable to read RDB block 0
>> nbd5: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd5: unable to read RDB block 0
>> nbd5: unable to read partition table
>> block nbd6: Send control failed (result -89)
>> block nbd6: Request send failed, requeueing
>> block nbd6: Dead connection, failed to find a fallback
>> block nbd6: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd6: unable to read RDB block 0
>> nbd6: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd6: unable to read RDB block 0
>> nbd6: unable to read partition table
>> block nbd7: Send control failed (result -89)
>> block nbd7: Request send failed, requeueing
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd7: unable to read RDB block 0
>> nbd7: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd7: unable to read RDB block 0
>> nbd7: unable to read partition table
>> block nbd8: Send control failed (result -89)
>> block nbd8: Request send failed, requeueing
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd8: unable to read RDB block 0
>> nbd8: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd8: unable to read RDB block 0
>> nbd8: unable to read partition table
>> block nbd9: Send control failed (result -32)
>> block nbd9: Request send failed, requeueing
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd9: unable to read RDB block 0
>> nbd9: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd9: unable to read RDB block 0
>> nbd9: unable to read partition table
>> block nbd10: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd10: unable to read RDB block 0
>> nbd10: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd10: unable to read RDB block 0
>> nbd10: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd11: unable to read RDB block 0
>> nbd11: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd11: unable to read RDB block 0
>> nbd11: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd12: unable to read RDB block 0
>> nbd12: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd12: unable to read RDB block 0
>> nbd12: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd13: unable to read RDB block 0
>> nbd13: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd13: unable to read RDB block 0
>> nbd13: unable to read partition table
>> nbd_send_cmd: 5 callbacks suppressed
>> block nbd14: Send control failed (result -89)
>> nbd_send_cmd: 5 callbacks suppressed
>> block nbd14: Request send failed, requeueing
>> block nbd14: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd14: unable to read RDB block 0
>> nbd14: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd14: unable to read RDB block 0
>> nbd14: unable to read partition table
>> block nbd15: Send control failed (result -89)
>> block nbd15: Request send failed, requeueing
>> block nbd15: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd15: unable to read RDB block 0
>> nbd15: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd15: unable to read RDB block 0
>> nbd15: unable to read partition table
>> block nbd16: Send control failed (result -89)
>> block nbd16: Request send failed, requeueing
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd16: unable to read RDB block 0
>> nbd16: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd16: unable to read RDB block 0
>> nbd16: unable to read partition table
>> block nbd17: Send control failed (result -89)
>> block nbd17: Request send failed, requeueing
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd17: unable to read RDB block 0
>> nbd17: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd17: unable to read RDB block 0
>> nbd17: unable to read partition table
>> block nbd18: Send control failed (result -89)
>> block nbd18: Request send failed, requeueing
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd18: unable to read RDB block 0
>> nbd18: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd18: unable to read RDB block 0
>> nbd18: unable to read partition table
>> block nbd19: Send control failed (result -89)
>> block nbd19: Request send failed, requeueing
>> block nbd19: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd19: unable to read RDB block 0
>> nbd19: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd19: unable to read RDB block 0
>> nbd19: unable to read partition table
>> block nbd20: Send control failed (result -89)
>> block nbd20: Request send failed, requeueing
>> block nbd20: Dead connection, failed to find a fallback
>> blk_print_req_error: 2802 callbacks suppressed
>> I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> buffer_io_error: 2802 callbacks suppressed
>> Buffer I/O error on dev nbd20, logical block 1, async page read
>> I/O error, dev nbd20, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd20, logical block 2, async page read
>> I/O error, dev nbd20, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd20, logical block 3, async page read
>> I/O error, dev nbd20, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd20, logical block 0, async page read
>> I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd20, logical block 1, async page read
>> I/O error, dev nbd20, sector 4 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd20, logical block 2, async page read
>> I/O error, dev nbd20, sector 6 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd20, logical block 3, async page read
>> I/O error, dev nbd20, sector 0 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd20, logical block 0, async page read
>> I/O error, dev nbd20, sector 2 op 0x0:(READ) flags 0x0 phys_seg 1 prio class 2
>> Buffer I/O error on dev nbd20, logical block 1, async page read
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd20: unable to read RDB block 0
>> nbd20: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd20: unable to read RDB block 0
>> nbd20: unable to read partition table
>> block nbd21: Send control failed (result -89)
>> block nbd21: Request send failed, requeueing
>> block nbd21: Dead connection, failed to find a fallback
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd21: unable to read RDB block 0
>> nbd21: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd21: unable to read RDB block 0
>> nbd21: unable to read partition table
>> block nbd22: Send control failed (result -89)
>> block nbd22: Request send failed, requeueing
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd22: unable to read RDB block 0
>> nbd22: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd22: unable to read RDB block 0
>> nbd22: unable to read partition table
>> block nbd23: Send control failed (result -89)
>> block nbd23: Request send failed, requeueing
>> block nbd23: Dead connection, failed to find a fallback
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd23: unable to read RDB block 0
>> nbd23: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd23: unable to read RDB block 0
>> nbd23: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd24: unable to read RDB block 0
>> nbd24: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd24: unable to read RDB block 0
>> nbd24: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd25: unable to read RDB block 0
>> nbd25: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd25: unable to read RDB block 0
>> nbd25: unable to read partition table
>> block nbd26: Dead connection, failed to find a fallback
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd26: unable to read RDB block 0
>> nbd26: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd26: unable to read RDB block 0
>> nbd26: unable to read partition table
>> block nbd27: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd27: unable to read RDB block 0
>> nbd27: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd27: unable to read RDB block 0
>> nbd27: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd28: unable to read RDB block 0
>> nbd28: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd28: unable to read RDB block 0
>> nbd28: unable to read partition table
>> block nbd29: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd29: unable to read RDB block 0
>> nbd29: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd29: unable to read RDB block 0
>> nbd29: unable to read partition table
>> block nbd30: shutting down sockets
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd30: unable to read RDB block 0
>> nbd30: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd30: unable to read RDB block 0
>> nbd30: unable to read partition table
>> ldm_validate_partition_table(): Disk read failed.
>> Dev nbd31: unable to read RDB block 0
>> nbd31: unable to read partition table
>>
>>
>> ---
>> This report is generated by a bot. It may contain errors.
>> See https://goo.gl/tpsmEJ for more information about syzbot.
>> syzbot engineers can be reached at syzkaller@googlegroups.com.
>>
>> syzbot will keep track of this issue. See:
>> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
>>
>> If the report is already addressed, let syzbot know by replying with:
>> #syz fix: exact-commit-title
>>
>> If you want syzbot to run the reproducer, reply with:
>> #syz test: git://repo/address.git branch-or-commit-hash
>> If you attach or paste a git patch, syzbot will apply it before testing.
>>
>> If you want to overwrite report's subsystems, reply with:
>> #syz set subsystems: new-subsystem
>> (See the list of subsystem names on the web dashboard)
>>
>> If the report is a duplicate of another one, reply with:
>> #syz dup: exact-subject-of-another-report
>>
>> If you want to undo deduplication, reply with:
>> #syz undup
>
> Question to NBD maintainers.
>
> What socket types are supposed to be supported by NBD ?
>
> I was thinking adding a list of supported ones, assuming TCP and
> stream unix are the only ones:
>
> diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
> index 6463d0e8d0ce..87b0b78249da 100644
> --- a/drivers/block/nbd.c
> +++ b/drivers/block/nbd.c
> @@ -1217,6 +1217,14 @@ static struct socket *nbd_get_socket(struct
> nbd_device *nbd, unsigned long fd,
> if (!sock)
> return NULL;
>
> + if (!sk_is_tcp(sock->sk) &&
> + !sk_is_stream_unix(sock->sk)) {
> + dev_err(disk_to_dev(nbd->disk), "Unsupported socket:
> should be TCP or UNIX.\n");
> + *err = -EINVAL;
> + sockfd_put(sock);
> + return NULL;
> + }
> +
> if (sock->ops->shutdown == sock_no_shutdown) {
> dev_err(disk_to_dev(nbd->disk), "Unsupported socket:
> shutdown callout must be supported.\n");
> *err = -EINVAL;
I think that'd be fine, actually surprised it currently allows other
types. Guess nobody thought of that before?!
--
Jens Axboe
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-08 9:40 ` Eric Dumazet
@ 2025-09-09 9:16 ` Yu Kuai
2025-09-09 9:31 ` Eric Dumazet
0 siblings, 1 reply; 11+ messages in thread
From: Yu Kuai @ 2025-09-09 9:16 UTC (permalink / raw)
To: Eric Dumazet, Yu Kuai
Cc: syzbot, Josef Bacik, Jens Axboe, davem, dsahern, horms, kuba,
linux-block, linux-kernel, ming.lei, netdev, pabeni,
syzkaller-bugs, thomas.hellstrom, yukuai (C)
Hi,
在 2025/09/08 17:40, Eric Dumazet 写道:
> On Mon, Sep 8, 2025 at 2:34 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>>
>> Hi,
>>
>> 在 2025/09/08 17:07, Eric Dumazet 写道:
>>> On Mon, Sep 8, 2025 at 1:52 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>>>>
>>>> Hi,
>>>>
>>>> 在 2025/09/06 17:16, Eric Dumazet 写道:
>>>>> On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@google.com> wrote:
>>>>>>
>>>>>> On Fri, Sep 5, 2025 at 1:00 PM syzbot
>>>>>> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
>>>>>
>>>>> Note to NBD maintainers : I held about 20 syzbot reports all pointing
>>>>> to NBD accepting various sockets, I can release them if needed, if you prefer
>>>>> to triage them.
>>>>>
>>>> I'm not NBD maintainer, just trying to understand the deadlock first.
>>>>
>>>> Is this deadlock only possible for some sepecific socket types? Take
>>>> a look at the report here:
>>>>
>>>> Usually issue IO will require the order:
>>>>
>>>> q_usage_counter -> cmd lock -> tx lock -> sk lock
>>>>
>>>
>>> I have not seen the deadlock being reported with normal TCP sockets.
>>>
>>> NBD sets sk->sk_allocation to GFP_NOIO | __GFP_MEMALLOC;
>>> from __sock_xmit(), and TCP seems to respect this.
>>> .
>>>
>>
>> What aboud iscsi and nvme-tcp? and probably other drivers, where
>> sk_allocation is GFP_ATOMIC, do they have similar problem?
>>
>
> AFAIK after this fix, iscsi was fine.
>
> commit f4f82c52a0ead5ab363d207d06f81b967d09ffb8
> Author: Eric Dumazet <edumazet@google.com>
> Date: Fri Sep 15 17:11:11 2023 +0000
>
> scsi: iscsi_tcp: restrict to TCP sockets
>
> Nothing prevents iscsi_sw_tcp_conn_bind() to receive file descriptor
> pointing to non TCP socket (af_unix for example).
>
> Return -EINVAL if this is attempted, instead of crashing the kernel.
>
> Fixes: 7ba247138907 ("[SCSI] open-iscsi/linux-iscsi-5 Initiator:
> Initiator code")
> Signed-off-by: Eric Dumazet <edumazet@google.com>
> Cc: Lee Duncan <lduncan@suse.com>
> Cc: Chris Leech <cleech@redhat.com>
> Cc: Mike Christie <michael.christie@oracle.com>
> Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
> Cc: open-iscsi@googlegroups.com
> Cc: linux-scsi@vger.kernel.org
> Reviewed-by: Mike Christie <michael.christie@oracle.com>
> Signed-off-by: David S. Miller <davem@davemloft.net>
> .
>
Yes, now I also agree similiar fix in nbd make sense. Perhaps can you
cook a patch?
Thanks,
Kuai
^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [syzbot] [net?] possible deadlock in inet_shutdown
2025-09-09 9:16 ` Yu Kuai
@ 2025-09-09 9:31 ` Eric Dumazet
0 siblings, 0 replies; 11+ messages in thread
From: Eric Dumazet @ 2025-09-09 9:31 UTC (permalink / raw)
To: Yu Kuai
Cc: syzbot, Josef Bacik, Jens Axboe, davem, dsahern, horms, kuba,
linux-block, linux-kernel, ming.lei, netdev, pabeni,
syzkaller-bugs, thomas.hellstrom, yukuai (C)
On Tue, Sep 9, 2025 at 2:16 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
>
> Hi,
>
> 在 2025/09/08 17:40, Eric Dumazet 写道:
> > On Mon, Sep 8, 2025 at 2:34 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
> >>
> >> Hi,
> >>
> >> 在 2025/09/08 17:07, Eric Dumazet 写道:
> >>> On Mon, Sep 8, 2025 at 1:52 AM Yu Kuai <yukuai1@huaweicloud.com> wrote:
> >>>>
> >>>> Hi,
> >>>>
> >>>> 在 2025/09/06 17:16, Eric Dumazet 写道:
> >>>>> On Fri, Sep 5, 2025 at 1:03 PM Eric Dumazet <edumazet@google.com> wrote:
> >>>>>>
> >>>>>> On Fri, Sep 5, 2025 at 1:00 PM syzbot
> >>>>>> <syzbot+e1cd6bd8493060bd701d@syzkaller.appspotmail.com> wrote:
> >>>>>
> >>>>> Note to NBD maintainers : I held about 20 syzbot reports all pointing
> >>>>> to NBD accepting various sockets, I can release them if needed, if you prefer
> >>>>> to triage them.
> >>>>>
> >>>> I'm not NBD maintainer, just trying to understand the deadlock first.
> >>>>
> >>>> Is this deadlock only possible for some sepecific socket types? Take
> >>>> a look at the report here:
> >>>>
> >>>> Usually issue IO will require the order:
> >>>>
> >>>> q_usage_counter -> cmd lock -> tx lock -> sk lock
> >>>>
> >>>
> >>> I have not seen the deadlock being reported with normal TCP sockets.
> >>>
> >>> NBD sets sk->sk_allocation to GFP_NOIO | __GFP_MEMALLOC;
> >>> from __sock_xmit(), and TCP seems to respect this.
> >>> .
> >>>
> >>
> >> What aboud iscsi and nvme-tcp? and probably other drivers, where
> >> sk_allocation is GFP_ATOMIC, do they have similar problem?
> >>
> >
> > AFAIK after this fix, iscsi was fine.
> >
> > commit f4f82c52a0ead5ab363d207d06f81b967d09ffb8
> > Author: Eric Dumazet <edumazet@google.com>
> > Date: Fri Sep 15 17:11:11 2023 +0000
> >
> > scsi: iscsi_tcp: restrict to TCP sockets
> >
> > Nothing prevents iscsi_sw_tcp_conn_bind() to receive file descriptor
> > pointing to non TCP socket (af_unix for example).
> >
> > Return -EINVAL if this is attempted, instead of crashing the kernel.
> >
> > Fixes: 7ba247138907 ("[SCSI] open-iscsi/linux-iscsi-5 Initiator:
> > Initiator code")
> > Signed-off-by: Eric Dumazet <edumazet@google.com>
> > Cc: Lee Duncan <lduncan@suse.com>
> > Cc: Chris Leech <cleech@redhat.com>
> > Cc: Mike Christie <michael.christie@oracle.com>
> > Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
> > Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
> > Cc: open-iscsi@googlegroups.com
> > Cc: linux-scsi@vger.kernel.org
> > Reviewed-by: Mike Christie <michael.christie@oracle.com>
> > Signed-off-by: David S. Miller <davem@davemloft.net>
> > .
> >
>
> Yes, now I also agree similiar fix in nbd make sense. Perhaps can you
> cook a patch?
Sure I will send it ASAP.
^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2025-09-09 9:31 UTC | newest]
Thread overview: 11+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-05 20:00 [syzbot] [net?] possible deadlock in inet_shutdown syzbot
2025-09-05 20:03 ` Eric Dumazet
2025-09-06 9:16 ` Eric Dumazet
2025-09-08 8:52 ` Yu Kuai
2025-09-08 9:07 ` Eric Dumazet
2025-09-08 9:34 ` Yu Kuai
2025-09-08 9:40 ` Eric Dumazet
2025-09-09 9:16 ` Yu Kuai
2025-09-09 9:31 ` Eric Dumazet
2025-09-08 13:03 ` Hillf Danton
2025-09-08 14:26 ` Jens Axboe
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