WARNING in copy_user_generic_unrolled

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: f4cc0ed9 Linux 4.14.131
git tree: linux-4.14.y
console output: https://syzkaller.appspot.com/x/log.txt?x=1309e4f5a00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ab1953b2cdac00f5
dashboard link: https://syzkaller.appspot.com/bug?extid=6d21646adbea6a9b2ba3
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+6d2164...@syzkaller.appspotmail.com

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
handle_userfault.cold+0x3c/0x50 fs/userfaultfd.c:429
------------[ cut here ]------------
WARNING: CPU: 1 PID: 17320 at fs/super.c:1163 kill_block_super+0xc9/0xf0
fs/super.c:1163
Kernel panic - not syncing: panic_on_warn set ...

do_anonymous_page mm/memory.c:3125 [inline]
handle_pte_fault mm/memory.c:3987 [inline]
__handle_mm_fault+0x2b36/0x3470 mm/memory.c:4113
handle_mm_fault+0x293/0x7c0 mm/memory.c:4150
__do_page_fault+0x4c1/0xb80 arch/x86/mm/fault.c:1423
do_page_fault+0x71/0x511 arch/x86/mm/fault.c:1498
page_fault+0x25/0x50 arch/x86/entry/entry_64.S:1120
RIP: 0010:copy_user_generic_unrolled+0x86/0xc0
arch/x86/lib/copy_user_64.S:66
RSP: 0018:ffff8880a52e7b20 EFLAGS: 00010202
RAX: ffffed1014a5cf85 RBX: 0000000020013ff4 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000020013ff4 RDI: ffff8880a52e7c20
RBP: ffff8880a52e7b50 R08: 1ffff11014a5cf84 R09: ffffed1014a5cf85
R10: ffffed1014a5cf84 R11: ffff8880a52e7c27 R12: 0000000000000008
R13: ffff8880a52e7c20 R14: 00007ffffffff000 R15: 0000000020013ffc
copy_from_user include/linux/uaccess.h:147 [inline]
sctp_getsockopt_maxseg net/sctp/socket.c:6024 [inline]
sctp_getsockopt net/sctp/socket.c:6936 [inline]
sctp_getsockopt+0x2b4e/0x4d6b net/sctp/socket.c:6841
sock_common_getsockopt+0x94/0xd0 net/core/sock.c:2925
SYSC_getsockopt net/socket.c:1896 [inline]
SyS_getsockopt+0x126/0x1e0 net/socket.c:1878
do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292
entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x459519
RSP: 002b:00007f0128c57c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000037
RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000459519
RDX: 000000000000000d RSI: 0000000000000084 RDI: 0000000000000005
RBP: 000000000075bf20 R08: 0000000020002000 R09: 0000000000000000
R10: 0000000020013ff4 R11: 0000000000000246 R12: 00007f0128c586d4
R13: 00000000004cb960 R14: 00000000004d2a50 R15: 00000000ffffffff
CPU: 1 PID: 17320 Comm: syz-executor.5 Not tainted 4.14.131 #25
kobject: 'loop1' (ffff8880a49531a0): kobject_uevent_env
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
kobject: 'loop1' (ffff8880a49531a0): fill_kobj_path: path
= '/devices/virtual/block/loop1'
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
kobject: 'loop1' (ffff8880a49531a0): kobject_uevent_env
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:ffff88805d30fb98 EFLAGS: 00010246
RAX: 0000000000040000 RBX: 0000000000000000 RCX: ffffc90005e55000
kobject: 'loop1' (ffff8880a49531a0): fill_kobj_path: path
= '/devices/virtual/block/loop1'
RDX: 0000000000040000 RSI: ffffffff818d9da9 RDI: ffff8880a77c3a60
RBP: ffff88805d30fbb0 R08: ffff888057650240 R09: 0000000000000001
R10: 0000000000000000 R11: ffff888057650240 R12: ffff888094870300
R13: ffff8880a77c36c0 R14: ffff888094870300 R15: dffffc0000000000
deactivate_locked_super+0x74/0xe0 fs/super.c:319
sget_userns+0x9d9/0xc30 fs/super.c:537
sget+0xd6/0x120 fs/super.c:572
mount_bdev+0xd5/0x370 fs/super.c:1107
hfsplus_mount+0x35/0x40 fs/hfsplus/super.c:648
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
kobject: 'loop0' (ffff8880a4904f20): kobject_uevent_env
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
kobject: 'loop0' (ffff8880a4904f20): fill_kobj_path: path
= '/devices/virtual/block/loop0'
RIP: 0033:0x45bf6a
RSP: 002b:00007f2482cf7a88 EFLAGS: 00000206 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f2482cf7b40 RCX: 000000000045bf6a
RDX: 00007f2482cf7ae0 RSI: 0000000020000180 RDI: 00007f2482cf7b00
RBP: 0000000000000000 R08: 00007f2482cf7b40 R09: 00007f2482cf7ae0
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000005
R13: 00000000004c849c R14: 00000000004defd8 R15: 0000000000000004
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.