[syzbot] INFO: task hung in do_read_cache_folio

syzbot
2022-02-07T05:51:14Z

Hello,

syzbot found the following issue on:

HEAD commit: 27bb0b18c208 Merge tag 'linux-kselftest-kunit-fixes-5.17-r..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13c4f1cc700000
kernel config: https://syzkaller.appspot.com/x/.config?x=3e56c9b92aaaee24
dashboard link: https://syzkaller.appspot.com/bug?extid=be946efe33b2d9664348
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=154c5624700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+be946efe33b2d9664348@syzkaller.appspotmail.com

INFO: task udevd:3663 blocked for more than 143 seconds.
Not tainted 5.17.0-rc2-syzkaller-00054-g27bb0b18c208 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:udevd state:D stack:26280 pid: 3663 ppid: 2964 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:4986 [inline]
__schedule+0xab2/0x4db0 kernel/sched/core.c:6295
schedule+0xd2/0x260 kernel/sched/core.c:6368
io_schedule+0xee/0x170 kernel/sched/core.c:8407
folio_wait_bit_common+0x4f2/0xa90 mm/filemap.c:1322
folio_wait_bit mm/filemap.c:1471 [inline]
folio_wait_locked include/linux/pagemap.h:847 [inline]
folio_wait_locked include/linux/pagemap.h:844 [inline]
do_read_cache_folio+0x506/0x760 mm/filemap.c:3495
do_read_cache_page mm/filemap.c:3567 [inline]
read_cache_page+0x59/0x1c0 mm/filemap.c:3576
read_mapping_page include/linux/pagemap.h:641 [inline]
read_part_sector+0xf6/0x5b0 block/partitions/core.c:724
adfspart_check_ICS+0x9d/0xc90 block/partitions/acorn.c:360
check_partition block/partitions/core.c:148 [inline]
blk_add_partitions block/partitions/core.c:609 [inline]
bdev_disk_changed+0x629/0xf60 block/partitions/core.c:695
blkdev_get_whole+0x206/0x2d0 block/bdev.c:679
blkdev_get_by_dev.part.0+0x5c6/0xc70 block/bdev.c:813
blkdev_get_by_dev+0x6b/0x80 block/bdev.c:847
blkdev_open+0x154/0x2e0 block/fops.c:501
do_dentry_open+0x4b9/0x1240 fs/open.c:824
do_open fs/namei.c:3476 [inline]
path_openat+0x1c9e/0x2940 fs/namei.c:3609
do_filp_open+0x1aa/0x400 fs/namei.c:3636
do_sys_openat2+0x16d/0x4d0 fs/open.c:1214
do_sys_open fs/open.c:1230 [inline]
__do_sys_openat fs/open.c:1246 [inline]
__se_sys_openat fs/open.c:1241 [inline]
__x64_sys_openat+0x13f/0x1f0 fs/open.c:1241
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f27d7675697
RSP: 002b:00007ffc91e0e6e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f27d8f5d4a0 RCX: 00007f27d7675697
RDX: 00000000000a0800 RSI: 00007f27d8f3f370 RDI: 00000000ffffff9c
RBP: 00007f27d8f3f370 R08: 0000000000000001 R09: 00007ffc91fcb080
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000000a0800
R13: 00007f27d8f30940 R14: 0000000000000001 R15: 00007f27d8f222c0
</TASK>
INFO: task syz-executor.0:3687 blocked for more than 143 seconds.
Not tainted 5.17.0-rc2-syzkaller-00054-g27bb0b18c208 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor.0 state:D stack:28288 pid: 3687 ppid: 3667 flags:0x00000004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:4986 [inline]
__schedule+0xab2/0x4db0 kernel/sched/core.c:6295
schedule+0xd2/0x260 kernel/sched/core.c:6368
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:6427
__mutex_lock_common kernel/locking/mutex.c:673 [inline]
__mutex_lock+0xa32/0x12f0 kernel/locking/mutex.c:733
blkdev_put+0x99/0x950 block/bdev.c:902
blkdev_close+0x6a/0x80 block/fops.c:515
__fput+0x286/0x9f0 fs/file_table.c:311
task_work_run+0xdd/0x1a0 kernel/task_work.c:164
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_user_mode_loop kernel/entry/common.c:175 [inline]
exit_to_user_mode_prepare+0x27e/0x290 kernel/entry/common.c:207
__syscall_exit_to_user_mode_work kernel/entry/common.c:289 [inline]
syscall_exit_to_user_mode+0x19/0x60 kernel/entry/common.c:300
do_syscall_64+0x42/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7efd9b888c9b
RSP: 002b:00007ffd940a8da0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 00007efd9b888c9b
RDX: 0000001b30d20000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007efd9b9ea960 R08: 0000000000000000 R09: 00007ffd941ec080
R10: 00007ffd941ec090 R11: 0000000000000293 R12: 00000000001274c9
R13: 00007ffd940a8ea0 R14: 00007efd9b9e9030 R15: 0000000000000032
</TASK>

Showing all locks held in the system:
1 lock held by khungtaskd/27:
#0: ffffffff8bb81120 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6460
5 locks held by kworker/u4:2/44:
2 locks held by getty/3273:
#0: ffff88807f6b9098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:244
#1: ffffc90002b5b2e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xcf0/0x1230 drivers/tty/n_tty.c:2077
1 lock held by udevd/3663:
#0: ffff88801b222118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_get_by_dev.part.0+0x9b/0xc70 block/bdev.c:804
1 lock held by syz-executor.0/3687:
#0: ffff88801b222118 (&disk->open_mutex){+.+.}-{3:3}, at: blkdev_put+0x99/0x950 block/bdev.c:902

=============================================

NMI backtrace for cpu 1
CPU: 1 PID: 27 Comm: khungtaskd Not tainted 5.17.0-rc2-syzkaller-00054-g27bb0b18c208 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
nmi_cpu_backtrace.cold+0x47/0x144 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:212 [inline]
watchdog+0xc1d/0xf50 kernel/hung_task.c:369
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 1154 Comm: kworker/0:3 Not tainted 5.17.0-rc2-syzkaller-00054-g27bb0b18c208 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:prep_new_page mm/page_alloc.c:2436 [inline]
RIP: 0010:get_page_from_freelist+0xa8d/0x2f50 mm/page_alloc.c:4165
Code: 00 00 48 8b 7c 24 28 44 89 fe e8 6e 8d ff ff 8b 5c 24 14 83 e3 04 45 85 ff 0f 84 bd 18 00 00 f7 84 24 84 00 00 00 00 00 04 00 <0f> 85 76 19 00 00 85 db 0f 85 22 1a 00 00 48 8b 44 24 28 48 8d 78
RSP: 0018:ffffc900047c7838 EFLAGS: 00000006
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff88801d5c00c0 RSI: ffffffff81b4ee92 RDI: 0000000000000003
RBP: 000000000003d5f8 R08: 0000000000000002 R09: 0000000000000001
R10: ffffffff81c58582 R11: 000000000000001f R12: 0000000000000000
R13: dffffc0000000000 R14: ffff88813fffa700 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f46530a1600 CR3: 000000000b88e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
__alloc_pages+0x1b2/0x500 mm/page_alloc.c:5389
__alloc_pages_node include/linux/gfp.h:572 [inline]
kmem_getpages mm/slab.c:1378 [inline]
cache_grow_begin+0x75/0x350 mm/slab.c:2584
cache_alloc_refill+0x27f/0x380 mm/slab.c:2957
____cache_alloc mm/slab.c:3040 [inline]
____cache_alloc mm/slab.c:3023 [inline]
slab_alloc_node mm/slab.c:3241 [inline]
kmem_cache_alloc_node_trace+0x49c/0x5b0 mm/slab.c:3609
__do_kmalloc_node mm/slab.c:3631 [inline]
__kmalloc_node_track_caller+0x38/0x60 mm/slab.c:3646
kmalloc_reserve net/core/skbuff.c:354 [inline]
__alloc_skb+0xde/0x340 net/core/skbuff.c:426
alloc_skb include/linux/skbuff.h:1158 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:745 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:802 [inline]
nsim_dev_trap_report_work+0x29a/0xbc0 drivers/net/netdevsim/dev.c:843
process_one_work+0x9ac/0x1650 kernel/workqueue.c:2307
worker_thread+0x657/0x1110 kernel/workqueue.c:2454
kthread+0x2e9/0x3a0 kernel/kthread.c:377
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
----------------
Code disassembly (best guess):
0: 00 00 add %al,(%rax)
2: 48 8b 7c 24 28 mov 0x28(%rsp),%rdi
7: 44 89 fe mov %r15d,%esi
a: e8 6e 8d ff ff callq 0xffff8d7d
f: 8b 5c 24 14 mov 0x14(%rsp),%ebx
13: 83 e3 04 and $0x4,%ebx
16: 45 85 ff test %r15d,%r15d
19: 0f 84 bd 18 00 00 je 0x18dc
1f: f7 84 24 84 00 00 00 testl $0x40000,0x84(%rsp)
26: 00 00 04 00
* 2a: 0f 85 76 19 00 00 jne 0x19a6 <-- trapping instruction
30: 85 db test %ebx,%ebx
32: 0f 85 22 1a 00 00 jne 0x1a5a
38: 48 8b 44 24 28 mov 0x28(%rsp),%rax
3d: 48 rex.W
3e: 8d .byte 0x8d
3f: 78 .byte 0x78

---
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