syzbot


general protection fault in unlink_file_vma (2)

Status: upstream: reported C repro on 2023/06/26 06:54
Subsystems: mm reiserfs
[Documentation on labels]
Reported-by: syzbot+7fbdbd17a5bd6d01bc65@syzkaller.appspotmail.com
First crash: 293d, last: 99d
Cause bisection: the issue happens on the oldest tested release (bisect log)
Crash: BUG: unable to handle kernel paging request in ip6t_do_table (log)
Repro: C syz .config
  
Fix bisection: fixed by (bisect log) :
commit 6f861765464f43a71462d52026fbddfc858239a5
Author: Jan Kara <jack@suse.cz>
Date: Wed Nov 1 17:43:10 2023 +0000

  fs: Block writes to mounted block devices

  
Discussions (2)
Title Replies (including bot) Last reply
[syzbot] [reiserfs?] [fat?] [mm?] general protection fault in unlink_file_vma (2) 0 (2) 2024/03/02 04:13
[syzbot] Monthly mm report (Aug 2023) 0 (1) 2023/08/11 07:44
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in unlink_file_vma mm C done 1 1317d 1313d 15/26 fixed on 2020/11/16 12:12
android-54 KASAN: null-ptr-deref Write in unlink_file_vma 1 296d 296d 0/2 auto-obsoleted due to no activity on 2023/09/21 09:15
Fix bisection attempts (6)
Created Duration User Patch Repo Result
2024/03/01 18:18 9h53m bisect fix upstream job log (1)
2024/01/06 00:01 3h01m bisect fix upstream job log (0) log
2023/12/06 08:22 2h52m bisect fix upstream job log (0) log
2023/11/04 19:50 2h13m bisect fix upstream job log (0) log
2023/10/05 03:39 2h23m bisect fix upstream job log (0) log
2023/08/07 07:05 2h51m bisect fix upstream job log (0) log
Cause bisection attempts (2)
Created Duration User Patch Repo Result
2023/09/21 03:43 6h23m bisect upstream job log (0) log
2023/06/26 08:30 8h01m bisect upstream error job log (0)
marked invalid by nogikh@google.com

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000030: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000180-0x0000000000000187]
CPU: 0 PID: 4994 Comm: udevd Not tainted 6.4.0-rc7-syzkaller-00234-g547cc9be86f4 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:__lock_acquire+0xe01/0x5f30 kernel/locking/lockdep.c:4956
Code: 00 00 3b 05 01 b0 59 0f 0f 87 7a 09 00 00 41 be 01 00 00 00 e9 84 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 9e 33 00 00 49 81 3c 24 20 38 16 90 0f 84 cd f2
RSP: 0000:ffffc90003b0f5d8 EFLAGS: 00010016

RAX: dffffc0000000000 RBX: 1ffff92000761eec RCX: 0000000000000000
RDX: 0000000000000030 RSI: 0000000000000000 RDI: 0000000000000180
RBP: ffff888076abbb80 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff81d6f0d2 R12: 0000000000000180
R13: 0000000000000000 R14: 0000000000000180 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffff9 CR3: 00000000278f2000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5705 [inline]
 lock_acquire+0x1b1/0x520 kernel/locking/lockdep.c:5670
 down_write+0x92/0x200 kernel/locking/rwsem.c:1573
 i_mmap_lock_write include/linux/fs.h:485 [inline]
 unlink_file_vma+0x81/0x120 mm/mmap.c:128
 free_pgtables+0x147/0x930 mm/memory.c:386
 exit_mmap+0x29e/0x930 mm/mmap.c:3118
 __mmput+0x128/0x4c0 kernel/fork.c:1351
 mmput+0x60/0x70 kernel/fork.c:1373
 exit_mm kernel/exit.c:567 [inline]
 do_exit+0x9b0/0x29b0 kernel/exit.c:861
 do_group_exit+0xd4/0x2a0 kernel/exit.c:1024
 get_signal+0x2318/0x25b0 kernel/signal.c:2876
 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x11f/0x240 kernel/entry/common.c:204
 irqentry_exit_to_user_mode+0x9/0x40 kernel/entry/common.c:310
 exc_page_fault+0xc0/0x170 arch/x86/mm/fault.c:1593
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:570
RIP: 0033:0x7fd9a06c926e
Code: Unable to access opcode bytes at 0x7fd9a06c9244.
RSP: 002b:00007fffd3ceb1d0 EFLAGS: 00010202
RAX: 000056344395de44 RBX: fffffffffffffe60 RCX: 000000000000001f
RDX: 000056344395f79e RSI: 000056312086e010 RDI: 0000000000000001
RBP: 0000563120882320 R08: 0000000000000000 R09: 8ad69a18ea1c0cdc
R10: 00000000ffffffff R11: 0000000000000007 R12: fffffffffffffff1
R13: 000056311ea72040 R14: 0000000000000000 R15: 000056312086e910
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__lock_acquire+0xe01/0x5f30 kernel/locking/lockdep.c:4956
Code: 00 00 3b 05 01 b0 59 0f 0f 87 7a 09 00 00 41 be 01 00 00 00 e9 84 00 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 e2 48 c1 ea 03 <80> 3c 02 00 0f 85 9e 33 00 00 49 81 3c 24 20 38 16 90 0f 84 cd f2
RSP: 0000:ffffc90003b0f5d8 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: 1ffff92000761eec RCX: 0000000000000000
RDX: 0000000000000030 RSI: 0000000000000000 RDI: 0000000000000180
RBP: ffff888076abbb80 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffffffff81d6f0d2 R12: 0000000000000180
R13: 0000000000000000 R14: 0000000000000180 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffffffffffff9 CR3: 00000000278f2000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	00 00                	add    %al,(%rax)
   2:	3b 05 01 b0 59 0f    	cmp    0xf59b001(%rip),%eax        # 0xf59b009
   8:	0f 87 7a 09 00 00    	ja     0x988
   e:	41 be 01 00 00 00    	mov    $0x1,%r14d
  14:	e9 84 00 00 00       	jmpq   0x9d
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	4c 89 e2             	mov    %r12,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 9e 33 00 00    	jne    0x33d2
  34:	49 81 3c 24 20 38 16 	cmpq   $0xffffffff90163820,(%r12)
  3b:	90
  3c:	0f                   	.byte 0xf
  3d:	84 cd                	test   %cl,%ch
  3f:	f2                   	repnz

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/06/26 06:20 upstream 547cc9be86f4 09ffe269 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-kasan-gce-root general protection fault in unlink_file_vma
* Struck through repros no longer work on HEAD.