WARNING in __mutex_lock

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 4d31c4fa cxgb4: Update 1.23.3.0 as the latest firmware sup..
git tree: net
console output: https://syzkaller.appspot.com/x/log.txt?x=103ae90f200000
kernel config: https://syzkaller.appspot.com/x/.config?x=8dcdce25ea72bedf
dashboard link: https://syzkaller.appspot.com/bug?extid=5cfbab187983b6245d5d
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
CC: [adilger...@dilger.ca linux...@vger.kernel.org
linux-...@vger.kernel.org ty...@mit.edu net...@vger.kernel.org]

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+5cfbab...@syzkaller.appspotmail.com

------------[ cut here ]------------
DEBUG_LOCKS_WARN_ON(flags & MUTEX_FLAG_PICKUP)
WARNING: CPU: 1 PID: 5847 at kernel/locking/mutex.c:99
__mutex_trylock_or_owner kernel/locking/mutex.c:99 [inline]
WARNING: CPU: 1 PID: 5847 at kernel/locking/mutex.c:99 __mutex_trylock
kernel/locking/mutex.c:125 [inline]
WARNING: CPU: 1 PID: 5847 at kernel/locking/mutex.c:99 __mutex_lock_common
kernel/locking/mutex.c:927 [inline]
WARNING: CPU: 1 PID: 5847 at kernel/locking/mutex.c:99
__mutex_lock+0x494/0x1310 kernel/locking/mutex.c:1072
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 5847 Comm: syz-executor.5 Not tainted 5.1.0-rc2+ #145
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+0x172/0x1f0 lib/dump_stack.c:113
panic+0x2cb/0x65c kernel/panic.c:214
__warn.cold+0x20/0x45 kernel/panic.c:571
report_bug+0x263/0x2b0 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:179 [inline]
fixup_bug arch/x86/kernel/traps.c:174 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973
RIP: 0010:__mutex_trylock_or_owner kernel/locking/mutex.c:99 [inline]
RIP: 0010:__mutex_trylock kernel/locking/mutex.c:125 [inline]
RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:927 [inline]
RIP: 0010:__mutex_lock+0x494/0x1310 kernel/locking/mutex.c:1072
Code: 08 84 c9 0f 85 f0 0d 00 00 8b 0d 1b c0 4f 02 85 c9 0f 85 05 ff ff ff
48 c7 c6 40 26 6b 87 48 c7 c7 00 24 6b 87 e8 ea 82 34 fa <0f> 0b e9 eb fe
ff ff 80 3d 72 c2 4b 02 00 0f 85 14 fd ff ff e8 63
RSP: 0018:ffff888098e66ea0 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000000000
RDX: 000000000000805a RSI: ffffffff815ae3f6 RDI: ffffed10131ccdc6
RBP: ffff888098e67010 R08: ffff888043530300 R09: fffffbfff11335fd
R10: fffffbfff11335fc R11: ffffffff8899afe3 R12: fffffbfff14b913c
R13: ffffe8ffffd2e000 R14: ffff888043530300 R15: 0000000000000004
mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:1087
ext4_mb_group_or_file fs/ext4/mballoc.c:4209 [inline]
ext4_mb_initialize_context+0x7e6/0xbc0 fs/ext4/mballoc.c:4252
ext4_mb_new_blocks+0x5c4/0x3c70 fs/ext4/mballoc.c:4525
ext4_ext_map_blocks+0x2c28/0x5300 fs/ext4/extents.c:4397
ext4_map_blocks+0x8c5/0x18e0 fs/ext4/inode.c:636
mpage_map_one_extent fs/ext4/inode.c:2476 [inline]
mpage_map_and_submit_extent fs/ext4/inode.c:2525 [inline]
ext4_writepages+0x1e69/0x34e0 fs/ext4/inode.c:2877
do_writepages+0xfc/0x2a0 mm/page-writeback.c:2341
__filemap_fdatawrite_range+0x26d/0x340 mm/filemap.c:413
__filemap_fdatawrite mm/filemap.c:421 [inline]
filemap_flush+0x24/0x30 mm/filemap.c:448
ext4_alloc_da_blocks+0x227/0x380 fs/ext4/inode.c:3269
ext4_ind_migrate+0x4f9/0x6b0 fs/ext4/migrate.c:633
ext4_ioctl_setflags+0x6b3/0x7a0 fs/ext4/ioctl.c:375
ext4_ioctl+0x29f/0x4390 fs/ext4/ioctl.c:754
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:509 [inline]
do_vfs_ioctl+0xd6e/0x1390 fs/ioctl.c:696
ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
__do_sys_ioctl fs/ioctl.c:720 [inline]
__se_sys_ioctl fs/ioctl.c:718 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458209
Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7
48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff
ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f6e0634fc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458209
RDX: 0000000020000000 RSI: 0000000040086602 RDI: 0000000000000007
RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6e063506d4
R13: 00000000004c074d R14: 00000000004d27b8 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..


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[syzbot]

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