syzbot


general protection fault in open_or_create_special_dir

Status: upstream: reported C repro on 2024/03/16 08:27
Bug presence: origin:downstream
[Documentation on labels]
Reported-by: syzbot+0adbb066671e40ff6805@syzkaller.appspotmail.com
First crash: 130d, last: 15d
Bug presence (3)
Date Name Commit Repro Result
2024/03/16 android13-5.15-lts (ToT) 993bed180178 C [report] general protection fault in open_or_create_special_dir
2024/03/16 lts (merge base) 6139f2a02fe0 C Didn't crash
2024/03/30 upstream (ToT) 486291a0e624 C Didn't crash
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-10 general protection fault in open_or_create_special_dir C 8 21d 130d 0/2 upstream: reported C repro on 2024/03/16 07:55
android-6-1 general protection fault in open_or_create_special_dir origin:downstream C 3 17d 130d 0/2 upstream: reported C repro on 2024/03/16 08:33
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2024/07/08 16:40 41m bisect fix android13-5.15-lts OK (0) job log log
2024/05/31 03:58 34m bisect fix android13-5.15-lts 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: 1 PID: 312 Comm: syz-executor352 Not tainted 5.15.148-syzkaller-00718-g993bed180178 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/29/2024
RIP: 0010:d_really_is_positive include/linux/dcache.h:503 [inline]
RIP: 0010:open_or_create_special_dir+0x89/0x1d0 fs/incfs/vfs.c:459
Code: e8 3c ce 59 ff e9 07 01 00 00 e8 32 ce 59 ff 48 c7 c3 ea ff ff ff e9 f6 00 00 00 4c 89 6d d0 4c 8d 6b 30 4d 89 ef 49 c1 ef 03 <43> 80 3c 37 00 74 08 4c 89 ef e8 a8 de 9b ff 49 83 7d 00 00 74 26
RSP: 0018:ffffc90000b07a98 EFLAGS: 00010202
RAX: 0000000000000008 RBX: 0000000000000008 RCX: ffff88811f283b40
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88811ee113e8
RBP: ffffc90000b07ad0 R08: dffffc0000000000 R09: ffffed1023dc227e
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88811c0b4900
R13: 0000000000000038 R14: dffffc0000000000 R15: 0000000000000007
FS:  00007fe2ab8c36c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020008fc0 CR3: 000000011ee83000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 incfs_mount_fs+0x49b/0xa30 fs/incfs/vfs.c:1856
 legacy_get_tree+0xf1/0x190 fs/fs_context.c:611
 vfs_get_tree+0x88/0x290 fs/super.c:1517
 do_new_mount+0x2ba/0xb30 fs/namespace.c:3005
 path_mount+0x671/0x1070 fs/namespace.c:3335
 do_mount fs/namespace.c:3348 [inline]
 __do_sys_mount fs/namespace.c:3556 [inline]
 __se_sys_mount+0x2c4/0x3b0 fs/namespace.c:3533
 __x64_sys_mount+0xbf/0xd0 fs/namespace.c:3533
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fe2ab926b49
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 81 18 00 00 90 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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe2ab8c3218 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007fe2ab9b03f8 RCX: 00007fe2ab926b49
RDX: 0000000020000180 RSI: 00000000200000c0 RDI: 0000000020000080
RBP: 00007fe2ab9b03f0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe2ab97d0bc
R13: 0030656c69662f2e R14: 00007fff6e7d5530 R15: 00007fe2ab97d0d4
 </TASK>
Modules linked in:
---[ end trace b74d8b1343349fec ]---
RIP: 0010:d_really_is_positive include/linux/dcache.h:503 [inline]
RIP: 0010:open_or_create_special_dir+0x89/0x1d0 fs/incfs/vfs.c:459
Code: e8 3c ce 59 ff e9 07 01 00 00 e8 32 ce 59 ff 48 c7 c3 ea ff ff ff e9 f6 00 00 00 4c 89 6d d0 4c 8d 6b 30 4d 89 ef 49 c1 ef 03 <43> 80 3c 37 00 74 08 4c 89 ef e8 a8 de 9b ff 49 83 7d 00 00 74 26
RSP: 0018:ffffc90000b07a98 EFLAGS: 00010202
RAX: 0000000000000008 RBX: 0000000000000008 RCX: ffff88811f283b40
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff88811ee113e8
RBP: ffffc90000b07ad0 R08: dffffc0000000000 R09: ffffed1023dc227e
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88811c0b4900
R13: 0000000000000038 R14: dffffc0000000000 R15: 0000000000000007
FS:  00007fe2ab8c36c0(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fff6e7d55f8 CR3: 000000011ee83000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e8 3c ce 59 ff       	call   0xff59ce41
   5:	e9 07 01 00 00       	jmp    0x111
   a:	e8 32 ce 59 ff       	call   0xff59ce41
   f:	48 c7 c3 ea ff ff ff 	mov    $0xffffffffffffffea,%rbx
  16:	e9 f6 00 00 00       	jmp    0x111
  1b:	4c 89 6d d0          	mov    %r13,-0x30(%rbp)
  1f:	4c 8d 6b 30          	lea    0x30(%rbx),%r13
  23:	4d 89 ef             	mov    %r13,%r15
  26:	49 c1 ef 03          	shr    $0x3,%r15
* 2a:	43 80 3c 37 00       	cmpb   $0x0,(%r15,%r14,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	4c 89 ef             	mov    %r13,%rdi
  34:	e8 a8 de 9b ff       	call   0xff9bdee1
  39:	49 83 7d 00 00       	cmpq   $0x0,0x0(%r13)
  3e:	74 26                	je     0x66

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/03/16 08:26 android13-5.15-lts 993bed180178 d615901c .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in open_or_create_special_dir
2024/04/07 19:23 android13-5.15-lts 993bed180178 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in open_or_create_special_dir
2024/03/24 23:01 android13-5.15-lts 993bed180178 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in open_or_create_special_dir
2024/03/24 22:27 android13-5.15-lts 993bed180178 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-15 general protection fault in open_or_create_special_dir
* Struck through repros no longer work on HEAD.