syzbot


general protection fault in dtSplitUp

Status: upstream: reported C repro on 2022/10/15 11:58
Reported-by: syzbot+1d7194bb8a1776f5162f@syzkaller.appspotmail.com
First crash: 798d, last: 798d
Fix bisection the fix commit could be any of (bisect log):
  9d5c0b3a8e1a Linux 4.14.295
  e911713e40ca Linux 4.14.299
  
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 general protection fault in dtSplitUp C error 1 799d 799d 0/1 upstream: reported C repro on 2022/10/13 16:49
upstream general protection fault in dtSplitUp jfs C error done 2 375d 811d 25/28 fixed on 2024/01/30 15:47

Sample crash report:
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
Modules linked in:
CPU: 1 PID: 7984 Comm: syz-executor377 Not tainted 4.14.295-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
task: ffff8880aaf00640 task.stack: ffff8880b3378000
RIP: 0010:dtExtendPage fs/jfs/jfs_dtree.c:1673 [inline]
RIP: 0010:dtSplitUp+0x11c1/0x47d0 fs/jfs/jfs_dtree.c:1046
RSP: 0018:ffff8880b337f7e0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffff8880b337fcb0 RDI: ffff8880b337fb80
RBP: 0000000000000000 R08: ffffffff8b9a1db8 R09: 0000000000000004
R10: 0000000000000000 R11: ffff8880aaf00640 R12: ffff88808e3ad468
R13: ffff8880b337fb78 R14: ffff88808e3ad5a8 R15: ffff88808e3ad228
FS:  0000555556a8d300(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd9ff27cb8 CR3: 000000009b76f000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 dtInsert+0x77c/0x9e0 fs/jfs/jfs_dtree.c:875
 jfs_create.part.0+0x364/0x800 fs/jfs/namei.c:150
 jfs_create+0x35/0x50 fs/jfs/namei.c:90
 vfs_create+0x3e3/0x620 fs/namei.c:2935
 SYSC_mknodat fs/namei.c:3806 [inline]
 SyS_mknodat+0x2f4/0x470 fs/namei.c:3783
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f341cc1ee99
RSP: 002b:00007ffe6bb915b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000103
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f341cc1ee99
RDX: 0000000000000008 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00007f341cbde700 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000103 R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00083878000000f4 R15: 0000000000000000
Code: f6 f4 18 ff 48 8b 44 24 50 48 8b 74 24 18 48 8d 58 e8 48 89 1e e8 e0 f4 18 ff 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f 85 b8 2c 00 00 48 8b 33 48 85 f6 0f 85 18 1a 00 
RIP: dtExtendPage fs/jfs/jfs_dtree.c:1673 [inline] RSP: ffff8880b337f7e0
RIP: dtSplitUp+0x11c1/0x47d0 fs/jfs/jfs_dtree.c:1046 RSP: ffff8880b337f7e0
---[ end trace 9afa8b7de5625124 ]---
----------------
Code disassembly (best guess):
   0:	f6 f4                	div    %ah
   2:	18 ff                	sbb    %bh,%bh
   4:	48 8b 44 24 50       	mov    0x50(%rsp),%rax
   9:	48 8b 74 24 18       	mov    0x18(%rsp),%rsi
   e:	48 8d 58 e8          	lea    -0x18(%rax),%rbx
  12:	48 89 1e             	mov    %rbx,(%rsi)
  15:	e8 e0 f4 18 ff       	callq  0xff18f4fa
  1a:	48 89 da             	mov    %rbx,%rdx
  1d:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  24:	fc ff df
  27:	48 c1 ea 03          	shr    $0x3,%rdx
* 2b:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2f:	0f 85 b8 2c 00 00    	jne    0x2ced
  35:	48 8b 33             	mov    (%rbx),%rsi
  38:	48 85 f6             	test   %rsi,%rsi
  3b:	0f                   	.byte 0xf
  3c:	85 18                	test   %ebx,(%rax)
  3e:	1a 00                	sbb    (%rax),%al

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/10/15 11:57 linux-4.14.y 9d5c0b3a8e1a 67cb024c .config console log report syz C [disk image] [vmlinux] [mounted in repro] ci2-linux-4-14 general protection fault in dtSplitUp
* Struck through repros no longer work on HEAD.