INFO: task hung in sysv_new_inode

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 3f8a27f9e27b Linux 4.19.211
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=103ab7bd080000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b9277b418617afe
dashboard link: https://syzkaller.appspot.com/bug?extid=f7b7af56d4ee08739a84
compiler: gcc version 10.2.1 20210110 (Debian 10.2.1-6)

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+f7b7af...@syzkaller.appspotmail.com

VFS: Found a V7 FS (block size = 512) on device loop3
INFO: task syz-executor.1:6759 blocked for more than 140 seconds.
Not tainted 4.19.211-syzkaller #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1 D29464 6759 9107 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
schedule_preempt_disabled+0xf/0x20 kernel/sched/core.c:3619
__mutex_lock_common kernel/locking/mutex.c:1016 [inline]
__mutex_lock+0x5f0/0x1190 kernel/locking/mutex.c:1078
sysv_new_inode+0x133/0x1300 fs/sysv/ialloc.c:151
sysv_mknod fs/sysv/namei.c:67 [inline]
sysv_create+0x1d/0xe0 fs/sysv/namei.c:80
vfs_create+0x461/0x6c0 fs/namei.c:2913
do_mknodat.part.0+0x2ff/0x480 fs/namei.c:3768
do_mknodat fs/namei.c:3789 [inline]
__do_sys_mknodat fs/namei.c:3792 [inline]
__se_sys_mknodat fs/namei.c:3789 [inline]
__x64_sys_mknodat+0x116/0x160 fs/namei.c:3789
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f51c6d08279
Code: Bad RIP value.
RSP: 002b:00007f51c565c168 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 00007f51c6e1b050 RCX: 00007f51c6d08279
gfs2: gfs2 mount does not exist
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000005
RBP: 00007f51c6d622e9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffc5621fc2f R14: 00007f51c565c300 R15: 0000000000022000

Showing all locks held in the system:
1 lock held by khungtaskd/1571:
#0: 000000007bbab323 (rcu_read_lock){....}, at: debug_show_all_locks+0x53/0x265 kernel/locking/lockdep.c:4441
1 lock held by systemd-udevd/4696:
1 lock held by in:imklog/7795:
#0: 0000000022bb0b1e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x26f/0x310 fs/file.c:767
2 locks held by syz-executor.3/8161:
#0: 000000002deeb180 (&bdev->bd_mutex){+.+.}, at: __blkdev_put+0xfc/0x870 fs/block_dev.c:1806
#1: 00000000dc2a5b04 (loop_ctl_mutex){+.+.}, at: __loop_clr_fd+0x88/0xe50 drivers/block/loop.c:1080
2 locks held by kworker/u4:4/30812:
2 locks held by syz-executor.1/6755:
3 locks held by syz-executor.1/6759:
#0: 0000000003dc7bd8 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1579 [inline]
#0: 0000000003dc7bd8 (sb_writers#20){.+.+}, at: mnt_want_write+0x3a/0xb0 fs/namespace.c:360
#1: 0000000059d6bf19 (&type->i_mutex_dir_key#9/1){+.+.}, at: inode_lock_nested include/linux/fs.h:783 [inline]
#1: 0000000059d6bf19 (&type->i_mutex_dir_key#9/1){+.+.}, at: filename_create+0x15a/0x490 fs/namei.c:3638
#2: 000000004d1eaf4a (&sbi->s_lock#2){+.+.}, at: sysv_new_inode+0x133/0x1300 fs/sysv/ialloc.c:151
3 locks held by syz-executor.1/15111:
2 locks held by syz-executor.3/15115:
3 locks held by syz-executor.4/15116:

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

NMI backtrace for cpu 0
CPU: 0 PID: 1571 Comm: khungtaskd Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 15122 Comm: systemd-udevd Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022
RIP: 0010:lock_release+0xc/0x8b0 kernel/locking/lockdep.c:3917
Code: 00 4c 8b 4c 24 10 e9 9f fd ff ff 48 c7 c7 40 f7 36 8d e8 e7 17 4d 00 e9 dc fd ff ff 66 90 48 b8 00 00 00 00 00 fc ff df 41 57 <41> 56 41 55 49 89 d5 41 54 55 48 89 fd 53 48 83 ec 78 48 c7 44 24
RSP: 0000:ffff88809600fb30 EFLAGS: 00000207
RAX: dffffc0000000000 RBX: ffff88809600fd48 RCX: ffffffff81518c83
RDX: ffffffff819ec55f RSI: 0000000000000001 RDI: ffffffff89f85fa0
RBP: ffffea0002284ac0 R08: 0000000000000000 R09: ffffed101742455a
R10: ffff8880ba122ad3 R11: 0000000000000000 R12: 000000008a12b025
R13: ffff8880af356840 R14: ffff8880af356880 R15: 0000000000000000
FS: 00007f349baf68c0(0000) GS:ffff8880ba100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000056309c2aa3c0 CR3: 00000000b40ed000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
alloc_set_pte+0x927/0x1a00 mm/memory.c:3629
filemap_map_pages+0xd66/0x11c0 mm/filemap.c:2700
do_fault_around mm/memory.c:3776 [inline]
do_read_fault mm/memory.c:3810 [inline]
do_fault mm/memory.c:3944 [inline]
handle_pte_fault mm/memory.c:4175 [inline]
__handle_mm_fault+0x2a8e/0x41c0 mm/memory.c:4299
handle_mm_fault+0x436/0xb10 mm/memory.c:4336
__do_page_fault+0x68e/0xd60 arch/x86/mm/fault.c:1412
page_fault+0x1e/0x30 arch/x86/entry/entry_64.S:1205
RIP: 0033:0x56309c2aa3c0
Code: eb d6 0f b6 47 06 48 c1 e0 30 48 0b 42 20 48 89 c1 48 89 42 20 e9 73 ff ff ff b8 01 00 00 00 e9 ce fd ff ff 66 0f 1f 44 00 00 <48> 83 ec 08 48 85 ff 74 77 48 85 f6 0f 84 8e 00 00 00 48 8b 16 48
RSP: 002b:00007ffe87cf9978 EFLAGS: 00010202
RAX: 000056309c2ef990 RBX: 000056309cda71c0 RCX: 000000000000000e
RDX: 000056309cdb4e70 RSI: 000056309cda71d0 RDI: 00007ffe87cf9980
RBP: 0000000000003afb R08: 0000000000000000 R09: 000056309cdbe200
R10: 000000000000000f R11: 000056309c2ed9a0 R12: 0000000000003afb
R13: 000056309cdb06e0 R14: 000056309cda1010 R15: 000056309cda1028


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[syzbot]

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