WARNING in gfs2_kill_sb

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e861d067 Linux 4.14.127
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1710d8bea00000
kernel config: https://syzkaller.appspot.com/x/.config?x=811cd47e9cb8f2d1
dashboard link: https://syzkaller.appspot.com/bug?extid=e62575e0cbbcc323f2e9
compiler: gcc (GCC) 9.0.0 20181231 (experimental)

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+e62575...@syzkaller.appspotmail.com

slab_pre_alloc_hook mm/slab.h:421 [inline]
slab_alloc_node mm/slab.c:3297 [inline]
kmem_cache_alloc_node+0x287/0x780 mm/slab.c:3640
__alloc_skb+0x9c/0x500 net/core/skbuff.c:193
alloc_skb include/linux/skbuff.h:980 [inline]
sock_wmalloc+0xae/0xf0 net/core/sock.c:1928
__ip6_append_data.isra.0+0x2292/0x2ac0 net/ipv6/ip6_output.c:1426
------------[ cut here ]------------
WARNING: CPU: 0 PID: 29440 at fs/super.c:1163 kill_block_super+0xc9/0xf0
fs/super.c:1163
Kernel panic - not syncing: panic_on_warn set ...

ip6_append_data+0x1b8/0x2f0 net/ipv6/ip6_output.c:1582
rawv6_sendmsg+0x1001/0x2d70 net/ipv6/raw.c:952
inet_sendmsg+0x122/0x500 net/ipv4/af_inet.c:762
sock_sendmsg_nosec net/socket.c:646 [inline]
sock_sendmsg+0xce/0x110 net/socket.c:656
SYSC_sendto+0x206/0x310 net/socket.c:1763
SyS_sendto+0x40/0x50 net/socket.c:1731
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x4592c9
RSP: 002b:00007f6d29418c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f6d29418c90 RCX: 00000000004592c9
RDX: 000000000000ff19 RSI: 0000000020000000 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 00000000000101aa
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6d294196d4
R13: 00000000004c707f R14: 00000000004dc260 R15: 0000000000000005
CPU: 0 PID: 29440 Comm: syz-executor.5 Not tainted 4.14.127 #21
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:17 [inline]
dump_stack+0x138/0x19c lib/dump_stack.c:53
panic+0x1f2/0x426 kernel/panic.c:182
__warn.cold+0x2f/0x36 kernel/panic.c:546
report_bug+0x216/0x254 lib/bug.c:186
fixup_bug arch/x86/kernel/traps.c:177 [inline]
fixup_bug arch/x86/kernel/traps.c:172 [inline]
do_error_trap+0x1bb/0x310 arch/x86/kernel/traps.c:295
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314
invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:960
RIP: 0010:kill_block_super+0xc9/0xf0 fs/super.c:1163
RSP: 0018:ffff8880587dfa48 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90005e3d000
RDX: 0000000000040000 RSI: ffffffff818d9ca9 RDI: ffff888087944be0
RBP: ffff8880587dfa60 R08: ffff888068114380 R09: 0000000000000001
R10: 0000000000000000 R11: ffff888068114380 R12: ffff888064e8c340
R13: ffff888087944840 R14: ffff888064e8c340 R15: dffffc0000000000
gfs2_kill_sb+0x14e/0x1a0 fs/gfs2/ops_fstype.c:1384
deactivate_locked_super+0x74/0xe0 fs/super.c:319
sget_userns+0x9d9/0xc30 fs/super.c:537
sget+0xd6/0x120 fs/super.c:572
gfs2_mount+0x13e/0x556 fs/gfs2/ops_fstype.c:1278
mount_fs+0x97/0x2a1 fs/super.c:1237
vfs_kern_mount.part.0+0x5e/0x3d0 fs/namespace.c:1046
vfs_kern_mount fs/namespace.c:1036 [inline]
do_new_mount fs/namespace.c:2549 [inline]
do_mount+0x417/0x27d0 fs/namespace.c:2879
SYSC_mount fs/namespace.c:3095 [inline]
SyS_mount+0xab/0x120 fs/namespace.c:3072
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x45bd1a
RSP: 002b:00007f79f3b38a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f79f3b38b40 RCX: 000000000045bd1a
RDX: 00007f79f3b38ae0 RSI: 0000000020000040 RDI: 00007f79f3b38b00
RBP: 0000000000000000 R08: 00007f79f3b38b40 R09: 00007f79f3b38ae0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000004
R13: 00000000004c8220 R14: 00000000004dea68 R15: 0000000000000003
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.