general protection fault in unlink_file_vma

syzbot
2020-09-09T00:19:22Z

Hello,

syzbot found the following issue on:

HEAD commit: 59126901 Merge tag 'perf-tools-fixes-for-v5.9-2020-09-03' ..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1166cb5d900000
kernel config: https://syzkaller.appspot.com/x/.config?x=3c5f6ce8d5b68299
dashboard link: https://syzkaller.appspot.com/bug?extid=c5d5a51dcbb558ca0cb5
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11901e95900000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15f56195900000

Bisection is inconclusive: the issue happens on the oldest tested release.

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1205faed900000
final oops: https://syzkaller.appspot.com/x/report.txt?x=1105faed900000
console output: https://syzkaller.appspot.com/x/log.txt?x=1605faed900000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+c5d5a51dcbb558ca0cb5@syzkaller.appspotmail.com

general protection fault, probably for non-canonical address 0xe00eeaee0000003b: 0000 [#1] PREEMPT SMP KASAN
KASAN: maybe wild-memory-access in range [0x00777770000001d8-0x00777770000001df]
CPU: 1 PID: 10488 Comm: syz-executor721 Not tainted 5.9.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unlink_file_vma+0x57/0xb0 mm/mmap.c:164
Code: 4c 8b a5 a0 00 00 00 4d 85 e4 74 4e e8 92 d7 cd ff 49 8d bc 24 d8 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 3d 4d 8b b4 24 d8 01 00 00 4d 8d 6e 78 4c 89 ef e8
RSP: 0018:ffffc9000ac0f9b0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88800010ceb0 RCX: ffffffff81592421
RDX: 000eeeee0000003b RSI: ffffffff81a6736e RDI: 00777770000001d8
RBP: ffff88800010ceb0 R08: 0000000000000001 R09: ffff88801291a50f
R10: ffffed10025234a1 R11: 0000000000000001 R12: 0077777000000000
R13: 00007f1eea0da000 R14: 00007f1eea0d9000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1eea11a9d0 CR3: 000000000007e000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
free_pgtables+0x1b3/0x2f0 mm/memory.c:415
exit_mmap+0x2c0/0x530 mm/mmap.c:3184
__mmput+0x122/0x470 kernel/fork.c:1076
mmput+0x53/0x60 kernel/fork.c:1097
exit_mm kernel/exit.c:483 [inline]
do_exit+0xa8b/0x29f0 kernel/exit.c:793
do_group_exit+0x125/0x310 kernel/exit.c:903
get_signal+0x428/0x1f00 kernel/signal.c:2757
arch_do_signal+0x82/0x2520 arch/x86/kernel/signal.c:811
exit_to_user_mode_loop kernel/entry/common.c:136 [inline]
exit_to_user_mode_prepare+0x1ae/0x200 kernel/entry/common.c:167
syscall_exit_to_user_mode+0x7e/0x2e0 kernel/entry/common.c:242
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x446ad9
Code: Bad RIP value.
RSP: 002b:00007f1eea0f8d18 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000006dbc58 RCX: 0000000000446ad9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00000000006dbc58
RBP: 00000000006dbc50 R08: 65732f636f72702f R09: 65732f636f72702f
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc5c
R13: 00007f1eea0f8d20 R14: 00007f1eea0f8d20 R15: 20c49ba5e353f7cf
Modules linked in:
---[ end trace 22e4d2773b69c9b0 ]---
RIP: 0010:unlink_file_vma+0x57/0xb0 mm/mmap.c:164
Code: 4c 8b a5 a0 00 00 00 4d 85 e4 74 4e e8 92 d7 cd ff 49 8d bc 24 d8 01 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 3d 4d 8b b4 24 d8 01 00 00 4d 8d 6e 78 4c 89 ef e8
RSP: 0018:ffffc9000ac0f9b0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88800010ceb0 RCX: ffffffff81592421
RDX: 000eeeee0000003b RSI: ffffffff81a6736e RDI: 00777770000001d8
RBP: ffff88800010ceb0 R08: 0000000000000001 R09: ffff88801291a50f
R10: ffffed10025234a1 R11: 0000000000000001 R12: 0077777000000000
R13: 00007f1eea0da000 R14: 00007f1eea0d9000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1eea11a9d0 CR3: 000000000007e000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
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