Re: [syzbot] [block?] possible deadlock in blk_mq_submit_bio

syzbot
2024-12-09T19:19:18Z

syzbot has found a reproducer for the following issue on:

HEAD commit: fac04efc5c79 Linux 6.13-rc2
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=100313e8580000
kernel config: https://syzkaller.appspot.com/x/.config?x=696fb014d05da3a3
dashboard link: https://syzkaller.appspot.com/bug?extid=5218c85078236fc46227
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=147528f8580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d219b605f6a9/disk-fac04efc.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/06776a2c689e/vmlinux-fac04efc.xz
kernel image: https://storage.googleapis.com/syzbot-assets/8ab42bd03182/Image-fac04efc.gz.xz
mounted in repro: https://storage.googleapis.com/syzbot-assets/c3180abcd8eb/mount_0.gz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5218c85078236fc46227@syzkaller.appspotmail.com

======================================================
WARNING: possible circular locking dependency detected
6.13.0-rc2-syzkaller-gfac04efc5c79 #0 Not tainted
------------------------------------------------------
syz.0.15/6643 is trying to acquire lock:
ffff0000c9f19de8 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: bio_queue_enter block/blk.h:79 [inline]
ffff0000c9f19de8 (&q->q_usage_counter(io)#17){++++}-{0:0}, at: blk_mq_submit_bio+0x11c8/0x2070 block/blk-mq.c:3092

but task is already holding lock:
ffff0000e7fcc0b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (&tree->tree_lock){+.+.}-{4:4}:
__mutex_lock_common+0x218/0x28f4 kernel/locking/mutex.c:585
__mutex_lock kernel/locking/mutex.c:735 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:787
hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28
hfsplus_cat_write_inode+0x1a4/0xd48 fs/hfsplus/inode.c:589
hfsplus_write_inode+0x15c/0x4dc fs/hfsplus/super.c:161
write_inode fs/fs-writeback.c:1525 [inline]
__writeback_single_inode+0x5a0/0x15a4 fs/fs-writeback.c:1745
writeback_single_inode+0x18c/0x554 fs/fs-writeback.c:1801
sync_inode_metadata+0xc4/0x12c fs/fs-writeback.c:2871
hfsplus_file_fsync+0xe4/0x4c8 fs/hfsplus/inode.c:316
vfs_fsync_range fs/sync.c:187 [inline]
vfs_fsync+0x154/0x18c fs/sync.c:201
__loop_update_dio+0x248/0x420 drivers/block/loop.c:204
loop_set_status+0x538/0x7f4 drivers/block/loop.c:1289
lo_ioctl+0xf10/0x1c48
blkdev_ioctl+0x3a8/0xa8c block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__arm64_sys_ioctl+0x14c/0x1cc fs/ioctl.c:892
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #1 (&sb->s_type->i_mutex_key#20){+.+.}-{4:4}:
down_write+0x50/0xc0 kernel/locking/rwsem.c:1577
inode_lock include/linux/fs.h:818 [inline]
hfsplus_file_fsync+0xd8/0x4c8 fs/hfsplus/inode.c:311
vfs_fsync_range fs/sync.c:187 [inline]
vfs_fsync+0x154/0x18c fs/sync.c:201
__loop_update_dio+0x248/0x420 drivers/block/loop.c:204
loop_set_status+0x538/0x7f4 drivers/block/loop.c:1289
lo_ioctl+0xf10/0x1c48
blkdev_ioctl+0x3a8/0xa8c block/ioctl.c:693
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:906 [inline]
__se_sys_ioctl fs/ioctl.c:892 [inline]
__arm64_sys_ioctl+0x14c/0x1cc fs/ioctl.c:892
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #0 (&q->q_usage_counter(io)#17){++++}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x34f0/0x7904 kernel/locking/lockdep.c:5226
lock_acquire+0x23c/0x724 kernel/locking/lockdep.c:5849
__bio_queue_enter+0x4dc/0x5b0 block/blk-core.c:361
bio_queue_enter block/blk.h:79 [inline]
blk_mq_submit_bio+0x11c8/0x2070 block/blk-mq.c:3092
__submit_bio+0x1a0/0x4f8 block/blk-core.c:629
__submit_bio_noacct_mq block/blk-core.c:710 [inline]
submit_bio_noacct_nocheck+0x3bc/0xcbc block/blk-core.c:739
submit_bio_noacct+0xc6c/0x166c block/blk-core.c:868
submit_bio+0x374/0x564 block/blk-core.c:910
submit_bh_wbc+0x3f8/0x4c8 fs/buffer.c:2814
submit_bh fs/buffer.c:2819 [inline]
block_read_full_folio+0x7ac/0x914 fs/buffer.c:2446
hfsplus_read_folio+0x28/0x38 fs/hfsplus/inode.c:28
filemap_read_folio+0x108/0x318 mm/filemap.c:2366
do_read_cache_folio+0x368/0x5c0 mm/filemap.c:3826
do_read_cache_page mm/filemap.c:3892 [inline]
read_cache_page+0x6c/0x15c mm/filemap.c:3901
read_mapping_page include/linux/pagemap.h:1005 [inline]
__hfs_bnode_create+0x3dc/0x6d4 fs/hfsplus/bnode.c:440
hfsplus_bnode_find+0x200/0xe60 fs/hfsplus/bnode.c:486
hfsplus_brec_find+0x134/0x4a0 fs/hfsplus/bfind.c:172
hfsplus_brec_read+0x38/0x128 fs/hfsplus/bfind.c:211
hfsplus_find_cat+0x140/0x4a0 fs/hfsplus/catalog.c:202
hfsplus_iget+0x34c/0x584 fs/hfsplus/super.c:83
hfsplus_fill_super+0xa5c/0x16f8 fs/hfsplus/super.c:504
get_tree_bdev_flags+0x38c/0x494 fs/super.c:1636
get_tree_bdev+0x2c/0x3c fs/super.c:1659
hfsplus_get_tree+0x28/0x38 fs/hfsplus/super.c:640
vfs_get_tree+0x90/0x28c fs/super.c:1814
do_new_mount+0x278/0x900 fs/namespace.c:3507
path_mount+0x590/0xe04 fs/namespace.c:3834
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4057 [inline]
__se_sys_mount fs/namespace.c:4034 [inline]
__arm64_sys_mount+0x4d4/0x5ac fs/namespace.c:4034
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

other info that might help us debug this:

Chain exists of:
&q->q_usage_counter(io)#17 --> &sb->s_type->i_mutex_key#20 --> &tree->tree_lock

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&tree->tree_lock);
lock(&sb->s_type->i_mutex_key#20);
lock(&tree->tree_lock);
rlock(&q->q_usage_counter(io)#17);

*** DEADLOCK ***

2 locks held by syz.0.15/6643:
#0: ffff0000e90420e0 (&type->s_umount_key#51/1){+.+.}-{4:4}, at: alloc_super+0x1b0/0x834 fs/super.c:344
#1: ffff0000e7fcc0b0 (&tree->tree_lock){+.+.}-{4:4}, at: hfsplus_find_init+0x144/0x1bc fs/hfsplus/bfind.c:28

stack backtrace:
CPU: 0 UID: 0 PID: 6643 Comm: syz.0.15 Not tainted 6.13.0-rc2-syzkaller-gfac04efc5c79 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call trace:
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:484 (C)
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
dump_stack+0x1c/0x28 lib/dump_stack.c:129
print_circular_bug+0x154/0x1c0 kernel/locking/lockdep.c:2074
check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x34f0/0x7904 kernel/locking/lockdep.c:5226
lock_acquire+0x23c/0x724 kernel/locking/lockdep.c:5849
__bio_queue_enter+0x4dc/0x5b0 block/blk-core.c:361
bio_queue_enter block/blk.h:79 [inline]
blk_mq_submit_bio+0x11c8/0x2070 block/blk-mq.c:3092
__submit_bio+0x1a0/0x4f8 block/blk-core.c:629
__submit_bio_noacct_mq block/blk-core.c:710 [inline]
submit_bio_noacct_nocheck+0x3bc/0xcbc block/blk-core.c:739
submit_bio_noacct+0xc6c/0x166c block/blk-core.c:868
submit_bio+0x374/0x564 block/blk-core.c:910
submit_bh_wbc+0x3f8/0x4c8 fs/buffer.c:2814
submit_bh fs/buffer.c:2819 [inline]
block_read_full_folio+0x7ac/0x914 fs/buffer.c:2446
hfsplus_read_folio+0x28/0x38 fs/hfsplus/inode.c:28
filemap_read_folio+0x108/0x318 mm/filemap.c:2366
do_read_cache_folio+0x368/0x5c0 mm/filemap.c:3826
do_read_cache_page mm/filemap.c:3892 [inline]
read_cache_page+0x6c/0x15c mm/filemap.c:3901
read_mapping_page include/linux/pagemap.h:1005 [inline]
__hfs_bnode_create+0x3dc/0x6d4 fs/hfsplus/bnode.c:440
hfsplus_bnode_find+0x200/0xe60 fs/hfsplus/bnode.c:486
hfsplus_brec_find+0x134/0x4a0 fs/hfsplus/bfind.c:172
hfsplus_brec_read+0x38/0x128 fs/hfsplus/bfind.c:211
hfsplus_find_cat+0x140/0x4a0 fs/hfsplus/catalog.c:202
hfsplus_iget+0x34c/0x584 fs/hfsplus/super.c:83
hfsplus_fill_super+0xa5c/0x16f8 fs/hfsplus/super.c:504
get_tree_bdev_flags+0x38c/0x494 fs/super.c:1636
get_tree_bdev+0x2c/0x3c fs/super.c:1659
hfsplus_get_tree+0x28/0x38 fs/hfsplus/super.c:640
vfs_get_tree+0x90/0x28c fs/super.c:1814
do_new_mount+0x278/0x900 fs/namespace.c:3507
path_mount+0x590/0xe04 fs/namespace.c:3834
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4057 [inline]
__se_sys_mount fs/namespace.c:4034 [inline]
__arm64_sys_mount+0x4d4/0x5ac fs/namespace.c:4034
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600
syz.0.15: attempt to access beyond end of device
loop0: rw=0, sector=208, nr_sectors = 2 limit=3
Buffer I/O error on dev loop0, logical block 104, async page read
syz.0.15: attempt to access beyond end of device
loop0: rw=0, sector=210, nr_sectors = 2 limit=3
Buffer I/O error on dev loop0, logical block 105, async page read
syz.0.15: attempt to access beyond end of device
loop0: rw=0, sector=212, nr_sectors = 2 limit=3
Buffer I/O error on dev loop0, logical block 106, async page read
hfsplus: failed to load root directory

---
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