syzbot


general protection fault in open_or_create_special_dir

Status: upstream: reported C repro on 2024/03/16 08:33
Bug presence: origin:downstream
[Documentation on labels]
Reported-by: syzbot+05dfbbbd5e79d4226531@syzkaller.appspotmail.com
First crash: 828d, last: 3d04h
Fix bisection: failed (error log, bisect log)
  
Bug presence (3)
Date Name Commit Repro Result
2024/03/16 android14-6.1 (ToT) ef39f76e4d24 C [report] general protection fault in open_or_create_special_dir
2024/03/16 lts (merge base) 883d1a956208 C Didn't crash
2024/03/30 upstream (ToT) 486291a0e624 C Didn't crash
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in open_or_create_special_dir 2 C 16 17d 828d 0/2 upstream: reported C repro on 2024/03/16 07:55
android-5-15 general protection fault in open_or_create_special_dir origin:downstream 2 C error 8 22d 828d 0/2 upstream: reported C repro on 2024/03/16 08:27
android-6-12 general protection fault in open_or_create_special_dir origin:downstream 2 C 4 60d 272d 0/1 internal: reported C repro on 2025/09/23 10:20
Last patch testing requests (9)
Created Duration User Patch Repo Result
2026/05/05 14:23 15m retest repro android14-6.1 report log
2026/04/14 01:44 6m retest repro android14-6.1 report log
2026/04/14 01:44 9m retest repro android14-6.1 report log
2026/04/14 01:44 6m retest repro android14-6.1 report log
2026/02/14 15:35 7m retest repro android14-6.1 report log
2026/01/31 14:28 6m retest repro android14-6.1 report log
2025/11/23 05:05 14m retest repro android14-6.1 report log
2025/09/13 07:33 10m retest repro android14-6.1 report log
2025/07/04 19:08 11m retest repro android14-6.1 report log
Fix bisection attempts (10)
Created Duration User Patch Repo Result
2025/04/25 16:25 2m bisect fix android14-6.1 error job log
2025/03/21 20:12 3h27m bisect fix android14-6.1 OK (0) job log log
2025/02/18 06:35 41m bisect fix android14-6.1 OK (0) job log log
2025/01/18 01:27 2h02m bisect fix android14-6.1 OK (0) job log log
2024/12/03 05:16 41m bisect fix android14-6.1 OK (0) job log log
2024/10/23 21:22 1h10m bisect fix android14-6.1 OK (0) job log log
2024/09/21 05:20 46m bisect fix android14-6.1 OK (0) job log log
2024/08/19 03:11 40m bisect fix android14-6.1 OK (0) job log log
2024/07/07 06:21 42m bisect fix android14-6.1 OK (0) job log log
2024/05/31 04:35 43m bisect fix android14-6.1 OK (0) job log log

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000007: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000038-0x000000000000003f]
CPU: 0 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:d_really_is_positive include/linux/dcache.h:493 [inline]
RIP: 0010:open_or_create_special_dir+0x85/0x1f0 fs/incfs/vfs.c:480
Code: 1b e8 0f 17 5a ff e9 21 01 00 00 e8 05 17 5a ff 48 c7 c3 ea ff ff ff e9 10 01 00 00 4c 89 f0 4c 8d 73 30 4d 89 f7 49 c1 ef 03 <41> 80 3c 07 00 74 08 4c 89 f7 e8 bc a1 9f ff 49 83 3e 00 74 2c e8
RSP: 0018:ffffc90000947b00 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000008 RCX: ffff888114751440
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: ffffc90000947b30 R08: ffff888123f16f67 R09: 1ffff110247e2dec
R10: dffffc0000000000 R11: ffffed10247e2ded R12: ffff888123f16ec0
R13: ffffc90000947b7f R14: 0000000000000038 R15: 0000000000000007
FS:  00007ff00afb46c0(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff00a1ea540 CR3: 000000012cf2a000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 incfs_mount_fs+0x42f/0x890 fs/incfs/vfs.c:1890
 legacy_get_tree+0xfe/0x1a0 fs/fs_context.c:632
 vfs_get_tree+0x9a/0x270 fs/super.c:1578
 do_new_mount+0x251/0xb40 fs/namespace.c:3081
 path_mount+0x640/0xfd0 fs/namespace.c:3411
 do_mount fs/namespace.c:3424 [inline]
 __do_sys_mount fs/namespace.c:3632 [inline]
 __se_sys_mount+0x320/0x390 fs/namespace.c:3609
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3609
 x64_sys_call+0x65d/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:166
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7ff00a19ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff00afb4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff00a415fa0 RCX: 00007ff00a19ce59
RDX: 0000200000000040 RSI: 0000200000000080 RDI: 0000200000000000
RBP: 00007ff00a232e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff00a416038 R14: 00007ff00a415fa0 R15: 00007ffcb106cc28
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:d_really_is_positive include/linux/dcache.h:493 [inline]
RIP: 0010:open_or_create_special_dir+0x85/0x1f0 fs/incfs/vfs.c:480
Code: 1b e8 0f 17 5a ff e9 21 01 00 00 e8 05 17 5a ff 48 c7 c3 ea ff ff ff e9 10 01 00 00 4c 89 f0 4c 8d 73 30 4d 89 f7 49 c1 ef 03 <41> 80 3c 07 00 74 08 4c 89 f7 e8 bc a1 9f ff 49 83 3e 00 74 2c e8
RSP: 0018:ffffc90000947b00 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000008 RCX: ffff888114751440
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 00000000ffffffff
RBP: ffffc90000947b30 R08: ffff888123f16f67 R09: 1ffff110247e2dec
R10: dffffc0000000000 R11: ffffed10247e2ded R12: ffff888123f16ec0
R13: ffffc90000947b7f R14: 0000000000000038 R15: 0000000000000007
FS:  00007ff00afb46c0(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff00af92ff8 CR3: 000000012cf2a000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	1b e8                	sbb    %eax,%ebp
   2:	0f 17 5a ff          	movhps %xmm3,-0x1(%rdx)
   6:	e9 21 01 00 00       	jmp    0x12c
   b:	e8 05 17 5a ff       	call   0xff5a1715
  10:	48 c7 c3 ea ff ff ff 	mov    $0xffffffffffffffea,%rbx
  17:	e9 10 01 00 00       	jmp    0x12c
  1c:	4c 89 f0             	mov    %r14,%rax
  1f:	4c 8d 73 30          	lea    0x30(%rbx),%r14
  23:	4d 89 f7             	mov    %r14,%r15
  26:	49 c1 ef 03          	shr    $0x3,%r15
* 2a:	41 80 3c 07 00       	cmpb   $0x0,(%r15,%rax,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 f7             	mov    %r14,%rdi
  34:	e8 bc a1 9f ff       	call   0xff9fa1f5
  39:	49 83 3e 00          	cmpq   $0x0,(%r14)
  3d:	74 2c                	je     0x6b
  3f:	e8                   	.byte 0xe8

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/19 15:28 android14-6.1 9f35ca3ff66c 570c59ee .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in open_or_create_special_dir
2026/03/30 23:46 android14-6.1 1c08e57193aa d0af506e .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro (corrupt fs)] ci2-android-6-1 general protection fault in open_or_create_special_dir
2026/03/22 01:00 android14-6.1 ddd5813c91fc 5b92003d .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in open_or_create_special_dir
2026/01/17 12:01 android14-6.1 f8a5ad1fcf13 20d37d28 .config console log report syz / log C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in open_or_create_special_dir
2024/03/16 08:32 android14-6.1 ef39f76e4d24 d615901c .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in open_or_create_special_dir
2024/04/08 09:03 android14-6.1 60534eef4739 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in open_or_create_special_dir
2024/04/07 19:23 android14-6.1 60534eef4739 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-6-1 general protection fault in open_or_create_special_dir
* Struck through repros no longer work on HEAD.