syzbot


general protection fault in dtInsertEntry

Status: upstream: reported C repro on 2022/09/25 23:44
Reported-by: syzbot+5e8b600d8a36c4a51f7d@syzkaller.appspotmail.com
First crash: 122d, last: 67d
similar bugs (2):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 general protection fault in dtInsertEntry C error 4 76d 122d 0/1 upstream: reported C repro on 2022/09/26 01:50
upstream BUG: unable to handle kernel NULL pointer dereference in dtInsertEntry C error 14 63d 122d 0/24 upstream: reported C repro on 2022/09/26 16:33

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: 0 PID: 7981 Comm: syz-executor296 Not tainted 4.14.295-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
task: ffff8880a51e4180 task.stack: ffff8880b2c78000
RIP: 0010:dtInsertEntry.isra.0+0x10a2/0x1440 fs/jfs/jfs_dtree.c:4018
RSP: 0018:ffff8880b2c7f558 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffc900015b9180
RDX: 0000000000000001 RSI: 0000000000000003 RDI: 0000000000000008
RBP: ffff888094dba446 R08: ffff8880b2c7f738 R09: ffff8880b2c7f718
R10: 0000000000000000 R11: ffff8880a51e4180 R12: ffff8880b0a0a59a
R13: dffffc0000000000 R14: 0000000000000073 R15: ffff888094dba428
FS:  00005555561a8300(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5b29900a00 CR3: 00000000b3142000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 dtInsert+0x47a/0x9e0 fs/jfs/jfs_dtree.c:898
 jfs_create.part.0+0x364/0x800 fs/jfs/namei.c:150
 jfs_create+0x35/0x50 fs/jfs/namei.c:90
 lookup_open+0x77a/0x1750 fs/namei.c:3241
 do_last fs/namei.c:3334 [inline]
 path_openat+0xe08/0x2970 fs/namei.c:3571
 do_filp_open+0x179/0x3c0 fs/namei.c:3605
 do_sys_open+0x296/0x410 fs/open.c:1081
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f5b29927029
RSP: 002b:00007fff1cee6208 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007f5b29927029
RDX: 000000000000275a RSI: 0000000020000040 RDI: 00000000ffffff9c
RBP: 00007f5b298e6890 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000f8008000
R13: 0000000000000000 R14: 00080000000000f8 R15: 0000000000000000
Code: c6 40 04 ff e9 9f f9 ff ff e8 4b 50 19 ff 48 8b 84 24 b0 00 00 00 48 8d 78 08 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 08 84 c0 0f 85 df 01 00 
RIP: dtInsertEntry.isra.0+0x10a2/0x1440 fs/jfs/jfs_dtree.c:4018 RSP: ffff8880b2c7f558
---[ end trace 4929664e99c93945 ]---
----------------
Code disassembly (best guess):
   0:	c6 40 04 ff          	movb   $0xff,0x4(%rax)
   4:	e9 9f f9 ff ff       	jmpq   0xfffff9a8
   9:	e8 4b 50 19 ff       	callq  0xff195059
   e:	48 8b 84 24 b0 00 00 	mov    0xb0(%rsp),%rax
  15:	00
  16:	48 8d 78 08          	lea    0x8(%rax),%rdi
  1a:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  21:	fc ff df
  24:	48 89 fa             	mov    %rdi,%rdx
  27:	48 c1 ea 03          	shr    $0x3,%rdx
* 2b:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2f:	48 89 fa             	mov    %rdi,%rdx
  32:	83 e2 07             	and    $0x7,%edx
  35:	38 d0                	cmp    %dl,%al
  37:	7f 08                	jg     0x41
  39:	84 c0                	test   %al,%al
  3b:	0f                   	.byte 0xf
  3c:	85 df                	test   %ebx,%edi
  3e:	01 00                	add    %eax,(%rax)

Fix bisection attempts:
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-14 2022/11/20 15:24 linux-4.14.y e911713e40ca feb56351 .config console log report syz C
* Struck through repros no longer work on HEAD.
Crashes (3):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets Title
ci2-linux-4-14 2022/10/03 06:40 linux-4.14.y 9d5c0b3a8e1a feb56351 .config console log report syz C [disk image] [vmlinux] general protection fault in dtInsertEntry
ci2-linux-4-14 2022/09/25 23:44 linux-4.14.y 4edbf74132a4 0042f2b4 .config console log report syz C [disk image] [vmlinux] general protection fault in dtInsertEntry
ci2-linux-4-14 2022/10/21 06:35 linux-4.14.y 9d5c0b3a8e1a a0fd4dab .config console log report info [disk image] [vmlinux] general protection fault in dtInsertEntry
* Struck through repros no longer work on HEAD.