general protection fault in mm_update_next_owner

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: dda0e292 Linux 4.19.114
git tree: linux-4.19.y
console output: https://syzkaller.appspot.com/x/log.txt?x=14210020100000
kernel config: https://syzkaller.appspot.com/x/.config?x=f32ac7e5b2d5c341
dashboard link: https://syzkaller.appspot.com/bug?extid=f8017a9aac61ba6c069b
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+f8017a...@syzkaller.appspotmail.com

audit: type=1804 audit(1586656430.436:579): pid=26278 uid=0 auid=0 ses=4 subj=system_u:system_r:kernel_t:s0 op=invalid_pcr cause=open_writers comm="syz-executor.1" name="/root/syzkaller-testdir290686321/syzkaller.lPIlZO/482/bus" dev="sda1" ino=16155 res=1
caif:caif_disconnect_client(): nothing to disconnect
caif:caif_disconnect_client(): nothing to disconnect
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 26269 Comm: syz-executor.0 Not tainted 4.19.114-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline]
RIP: 0010:mm_update_next_owner+0x3c6/0x650 kernel/exit.c:452
Code: 48 8d bd 30 03 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 52 02 00 00 48 8b ad 30 03 00 00 4c 8d 6d 10 4c 89 e8 48 c1 e8 03 <80> 3c 18 00 0f 85 29 02 00 00 48 8b 45 10 48 8d a8 70 fa ff ff 49
RSP: 0018:ffff88821885fd40 EFLAGS: 00010202
RAX: 0000000000000002 RBX: dffffc0000000000 RCX: ffffffff813dd21e
RDX: 0000000000000000 RSI: ffffffff813dd22c RDI: ffff888000112ac0
RBP: 0000000000000000 R08: ffff888036c585c0 R09: fffffbfff1141219
R10: fffffbfff1141218 R11: ffffffff88a090c3 R12: ffff8880a8160ec0
R13: 0000000000000010 R14: ffff888036c585c0 R15: ffff88803c890400
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f240809d000 CR3: 0000000096774000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
exit_mm kernel/exit.c:545 [inline]
do_exit+0xac0/0x2f30 kernel/exit.c:867
do_group_exit+0x125/0x350 kernel/exit.c:983
__do_sys_exit_group kernel/exit.c:994 [inline]
__se_sys_exit_group kernel/exit.c:992 [inline]
__x64_sys_exit_group+0x3a/0x50 kernel/exit.c:992
do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c889
Code: ad b6 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffcae49c918 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000001e RCX: 000000000045c889
RDX: 0000000000416421 RSI: fffffffffffffff7 RDI: 0000000000000000
RBP: 0000000000000000 R08: 01ffffffffffffff R09: 00007ffcae49c970
R10: 0000000000771070 R11: 0000000000000246 R12: 0000000000000001
R13: 00007ffcae49c970 R14: 0000000000000000 R15: 00007ffcae49c980
Modules linked in:
---[ end trace 9662a752853bb290 ]---
RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline]
RIP: 0010:mm_update_next_owner+0x3c6/0x650 kernel/exit.c:452
Code: 48 8d bd 30 03 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 52 02 00 00 48 8b ad 30 03 00 00 4c 8d 6d 10 4c 89 e8 48 c1 e8 03 <80> 3c 18 00 0f 85 29 02 00 00 48 8b 45 10 48 8d a8 70 fa ff ff 49
RSP: 0018:ffff88821885fd40 EFLAGS: 00010202
RAX: 0000000000000002 RBX: dffffc0000000000 RCX: ffffffff813dd21e
RDX: 0000000000000000 RSI: ffffffff813dd22c RDI: ffff888000112ac0
RBP: 0000000000000000 R08: ffff888036c585c0 R09: fffffbfff1141219
R10: fffffbfff1141218 R11: ffffffff88a090c3 R12: ffff8880a8160ec0
R13: 0000000000000010 R14: ffff888036c585c0 R15: ffff88803c890400
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f240809d000 CR3: 0000000096774000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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[syzbot]

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