INFO: task hung in filename_create (2)

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 255b58a2 Linux 4.19.176
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=111e2032d00000
kernel config: https://syzkaller.appspot.com/x/.config?x=b270830ae46c1d6f
dashboard link: https://syzkaller.appspot.com/bug?extid=4a0532a3ea2b64a66974

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+4a0532...@syzkaller.appspotmail.com

Bluetooth: hci5: command 0x0406 tx timeout
Bluetooth: hci2: command 0x0406 tx timeout
Bluetooth: hci3: command 0x0406 tx timeout
ieee802154 phy0 wpan0: encryption failed: -22
ieee802154 phy1 wpan1: encryption failed: -22
INFO: task syz-executor.4:9733 blocked for more than 140 seconds.
Not tainted 4.19.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D29952 9733 8132 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618
call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117
__down_write arch/x86/include/asm/rwsem.h:142 [inline]
down_write_nested+0x51/0x90 kernel/locking/rwsem.c:194
inode_lock_nested include/linux/fs.h:783 [inline]
filename_create+0x15a/0x490 fs/namei.c:3638
user_path_create fs/namei.c:3696 [inline]
do_mkdirat+0xa0/0x2d0 fs/namei.c:3834
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x466019
Code: 44 24 08 48 89 44 24 18 48 8b 4c 24 30 48 89 0c 24 48 8b 4c 24 38 48 89 4c 24 08 48 89 44 24 10 e8 2c a2 fa ff 48 8b 44 24 18 <48> 89 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 f3 47 00 00 eb 91
RSP: 002b:00007f134b264188 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 000000000056c008 RCX: 0000000000466019
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000200001c0
RBP: 00000000004bd067 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c008
R13: 00007ffc7ffcea4f R14: 00007f134b264300 R15: 0000000000022000
INFO: task syz-executor.4:9773 blocked for more than 140 seconds.
Not tainted 4.19.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D29464 9773 8132 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_read_failed_common kernel/locking/rwsem-xadd.c:292 [inline]
rwsem_down_read_failed+0x20a/0x390 kernel/locking/rwsem-xadd.c:309
call_rwsem_down_read_failed+0x14/0x30 arch/x86/lib/rwsem.S:94
__down_read arch/x86/include/asm/rwsem.h:83 [inline]
down_read+0x44/0x80 kernel/locking/rwsem.c:26
inode_lock_shared include/linux/fs.h:758 [inline]
lookup_slow fs/namei.c:1688 [inline]
walk_component+0x798/0xda0 fs/namei.c:1811
lookup_last fs/namei.c:2274 [inline]
path_lookupat+0x1ff/0x8d0 fs/namei.c:2319
filename_lookup+0x1ac/0x5a0 fs/namei.c:2349
user_path_at include/linux/namei.h:57 [inline]
ksys_chdir+0x84/0x1d0 fs/open.c:458
__do_sys_chdir fs/open.c:480 [inline]
__se_sys_chdir fs/open.c:478 [inline]
__x64_sys_chdir+0x2d/0x40 fs/open.c:478
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x466019
Code: 44 24 08 48 89 44 24 18 48 8b 4c 24 30 48 89 0c 24 48 8b 4c 24 38 48 89 4c 24 08 48 89 44 24 10 e8 2c a2 fa ff 48 8b 44 24 18 <48> 89 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 f3 47 00 00 eb 91
RSP: 002b:00007f134b201188 EFLAGS: 00000246 ORIG_RAX: 0000000000000050
RAX: ffffffffffffffda RBX: 000000000056c200 RCX: 0000000000466019
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000020000080
RBP: 00000000004bd067 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c200
R13: 00007ffc7ffcea4f R14: 00007f134b201300 R15: 0000000000022000
INFO: task syz-executor.4:9779 blocked for more than 140 seconds.
Not tainted 4.19.176-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.4 D29896 9779 8132 0x00000004
Call Trace:
context_switch kernel/sched/core.c:2828 [inline]
__schedule+0x887/0x2040 kernel/sched/core.c:3517
schedule+0x8d/0x1b0 kernel/sched/core.c:3561
__rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline]
rwsem_down_write_failed+0x3aa/0x760 kernel/locking/rwsem-xadd.c:618
call_rwsem_down_write_failed+0x13/0x20 arch/x86/lib/rwsem.S:117
__down_write arch/x86/include/asm/rwsem.h:142 [inline]
down_write_nested+0x51/0x90 kernel/locking/rwsem.c:194
inode_lock_nested include/linux/fs.h:783 [inline]
filename_create+0x15a/0x490 fs/namei.c:3638
unix_mknod net/unix/af_unix.c:984 [inline]
unix_bind+0x321/0xa40 net/unix/af_unix.c:1035
__sys_bind+0x1e9/0x250 net/socket.c:1482
__do_sys_bind net/socket.c:1493 [inline]
__se_sys_bind net/socket.c:1491 [inline]
__x64_sys_bind+0x6f/0xb0 net/socket.c:1491
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x466019
Code: 44 24 08 48 89 44 24 18 48 8b 4c 24 30 48 89 0c 24 48 8b 4c 24 38 48 89 4c 24 08 48 89 44 24 10 e8 2c a2 fa ff 48 8b 44 24 18 <48> 89 44 24 40 48 8b 6c 24 20 48 83 c4 28 c3 e8 f3 47 00 00 eb 91
RSP: 002b:00007f134b1e0188 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 000000000056c2a8 RCX: 0000000000466019
RDX: 000000000000006e RSI: 0000000020003000 RDI: 0000000000000008
RBP: 00000000004bd067 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c2a8
R13: 00007ffc7ffcea4f R14: 00007f134b1e0300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1565:
#0: 00000000d19d7080 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4440
1 lock held by in:imklog/7804:
2 locks held by syz-executor.4/9719:
#0: 000000004cbf258d (sb_writers#16){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
#0: 000000004cbf258d (sb_writers#16){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
#1: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#23/1){+.+.}, at: inode_lock_nested include/linux/fs.h:783 [inline]
#1: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#23/1){+.+.}, at: filename_create+0x15a/0x490 fs/namei.c:3638
2 locks held by syz-executor.4/9733:
#0: 000000004cbf258d (sb_writers#16){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
#0: 000000004cbf258d (sb_writers#16){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
#1: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#23/1){+.+.}, at: inode_lock_nested include/linux/fs.h:783 [inline]
#1: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#23/1){+.+.}, at: filename_create+0x15a/0x490 fs/namei.c:3638
1 lock held by syz-executor.4/9769:
#0: 00000000e0b50541 (&type->s_umount_key#52){+.+.}, at: deactivate_super+0x16c/0x1a0 fs/super.c:359
1 lock held by syz-executor.4/9773:
#0: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#24){.+.+}, at: inode_lock_shared include/linux/fs.h:758 [inline]
#0: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#24){.+.+}, at: lookup_slow fs/namei.c:1688 [inline]
#0: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#24){.+.+}, at: walk_component+0x798/0xda0 fs/namei.c:1811
2 locks held by syz-executor.4/9779:
#0: 000000004cbf258d (sb_writers#16){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
#0: 000000004cbf258d (sb_writers#16){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
#1: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#23/1){+.+.}, at: inode_lock_nested include/linux/fs.h:783 [inline]
#1: 00000000e2a3fc28 (&sb->s_type->i_mutex_key#23/1){+.+.}, at: filename_create+0x15a/0x490 fs/namei.c:3638

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

NMI backtrace for cpu 1
CPU: 1 PID: 1565 Comm: khungtaskd Not tainted 4.19.176-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
nmi_cpu_backtrace.cold+0x63/0xa2 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1a6/0x1f0 lib/nmi_backtrace.c:62
trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline]
check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline]
watchdog+0x991/0xe60 kernel/hung_task.c:287
kthread+0x33f/0x460 kernel/kthread.c:259
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7805 Comm: rs:main Q:Reg Not tainted 4.19.176-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:preempt_count_sub+0x21/0x150 kernel/sched/core.c:3262
Code: 1f 84 00 00 00 00 00 66 90 48 c7 c0 60 b7 23 8d 53 89 fb 48 ba 00 00 00 00 00 fc ff df 48 89 c1 83 e0 07 48 c1 e9 03 83 c0 03 <0f> b6 14 11 38 d0 7c 08 84 d2 0f 85 ef 00 00 00 8b 0d 89 47 e2 0b
RSP: 0018:ffff8880a11bf248 EFLAGS: 00000206
RAX: 0000000000000003 RBX: 0000000000000001 RCX: 1ffffffff1a476ec
RDX: dffffc0000000000 RSI: ffff8880a11bf1e8 RDI: 0000000000000001
RBP: ffff8880a11bf3e8 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000074071 R11: 0000000000000001 R12: ffff8880a11b8000
R13: ffff8880a11bf42d R14: ffff8880a11bf430 R15: ffff8880a11bf3f8
FS: 00007fc1773f6700(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f215db29000 CR3: 0000000092e0f000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
unwind_next_frame+0x10a9/0x1c60 arch/x86/kernel/unwind_orc.c:579
__unwind_start+0x5b8/0x960 arch/x86/kernel/unwind_orc.c:667
unwind_start arch/x86/include/asm/unwind.h:60 [inline]
__save_stack_trace+0x72/0x190 arch/x86/kernel/stacktrace.c:43
save_stack mm/kasan/kasan.c:448 [inline]
set_track mm/kasan/kasan.c:460 [inline]
kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:553
kmem_cache_alloc+0x122/0x370 mm/slab.c:3559
kmem_cache_zalloc include/linux/slab.h:699 [inline]
alloc_buffer_head+0x20/0x130 fs/buffer.c:3372
alloc_page_buffers+0x169/0x5c0 fs/buffer.c:830
create_empty_buffers+0x2c/0x760 fs/buffer.c:1528
create_page_buffers+0x212/0x350 fs/buffer.c:1645
__block_write_begin_int+0x22b/0x17b0 fs/buffer.c:1957
ext4_da_write_begin+0x4e1/0x10e0 fs/ext4/inode.c:3110
generic_perform_write+0x1f8/0x4d0 mm/filemap.c:3170
__generic_file_write_iter+0x24b/0x610 mm/filemap.c:3295
ext4_file_write_iter+0x2fe/0xf20 fs/ext4/file.c:272
call_write_iter include/linux/fs.h:1821 [inline]
new_sync_write fs/read_write.c:474 [inline]
__vfs_write+0x51b/0x770 fs/read_write.c:487
vfs_write+0x1f3/0x540 fs/read_write.c:549
ksys_write+0x12b/0x2a0 fs/read_write.c:599
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fc179e3a1cd
Code: c2 20 00 00 75 10 b8 01 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 ae fc ff ff 48 89 04 24 b8 01 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 f7 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fc1773f5590 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fc16c0264a0 RCX: 00007fc179e3a1cd
RDX: 0000000000000403 RSI: 00007fc16c0264a0 RDI: 0000000000000008
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 00007fc16c026220
R13: 00007fc1773f55b0 R14: 000055675ab15440 R15: 0000000000000403


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.