syzbot


general protection fault in vfs_link

Status: upstream: reported C repro on 2024/02/13 06:42
Reported-by: syzbot+9344e72989de4244c44a@syzkaller.appspotmail.com
First crash: 121d, last: 60d
Fix bisection: the issue occurs on the latest tested release (bisect log)
  
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-6-1 general protection fault in vfs_link origin:downstream C 1 16d 110d 0/2 upstream: reported C repro on 2024/02/23 21:10
android-5-15 general protection fault in vfs_link origin:downstream C 1 16d 109d 0/2 upstream: reported C repro on 2024/02/24 15:03
android-54 general protection fault in vfs_link C 1 29d 113d 0/2 upstream: reported C repro on 2024/02/20 15:20
Last patch testing requests (1)
Created Duration User Patch Repo Result
2024/02/27 06:36 7m retest repro android13-5.10-lts report log
Fix bisection attempts (2)
Created Duration User Patch Repo Result
2024/05/14 22:35 35m bisect fix android13-5.10-lts job log (0)
2024/04/13 18:48 2h25m bisect fix android13-5.10-lts job log (0) log

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
CPU: 0 PID: 286 Comm: syz-executor974 Not tainted 5.10.209-syzkaller-00423-gfc10db4b1932 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
RIP: 0010:vfs_link+0x3c/0x890 fs/namei.c:4175
Code: 89 4d a0 49 89 d4 49 89 f6 48 89 fb 49 bf 00 00 00 00 00 fc ff df e8 43 a0 b6 ff 48 89 5d a8 48 83 c3 30 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 25 17 f4 ff 48 8b 03 48 89 45 d0
RSP: 0018:ffffc90000967bd0 EFLAGS: 00010206
RAX: 0000000000000006 RBX: 0000000000000030 RCX: ffff88811e28cf00
RDX: 0000000000000000 RSI: ffff8881105c6018 RDI: 0000000000000000
RBP: ffffc90000967c30 R08: dffffc0000000000 R09: ffffed10220b8c19
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88811c4ceee0
R13: ffffc90000967cc8 R14: ffff8881105c6018 R15: dffffc0000000000
FS:  000055555608d480(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 000000011e27b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 incfs_link fs/incfs/vfs.c:604 [inline]
 dir_link+0x37f/0x510 fs/incfs/vfs.c:1279
 vfs_link+0x68f/0x890 fs/namei.c:4219
 do_linkat+0x471/0x8b0 fs/namei.c:4287
 __do_sys_linkat fs/namei.c:4311 [inline]
 __se_sys_linkat fs/namei.c:4308 [inline]
 __x64_sys_linkat+0xbf/0xd0 fs/namei.c:4308
 do_syscall_64+0x34/0x70
 entry_SYSCALL_64_after_hwframe+0x61/0xc6
RIP: 0033:0x7f24cc713c69
Code: 48 83 c4 28 c3 e8 37 17 00 00 0f 1f 80 00 00 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe3ec91ab8 EFLAGS: 00000246 ORIG_RAX: 0000000000000109
RAX: ffffffffffffffda RBX: 00007ffe3ec91ac0 RCX: 00007f24cc713c69
RDX: 0000000000000004 RSI: 0000000020000080 RDI: 0000000000000004
RBP: 00007ffe3ec91ac8 R08: 0000000000000000 R09: 00007f24cc6e3be0
R10: 0000000020000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffe3ec91d28 R14: 0000000000000001 R15: 0000000000000001
Modules linked in:
---[ end trace cc29ddc6fbc81186 ]---
RIP: 0010:vfs_link+0x3c/0x890 fs/namei.c:4175
Code: 89 4d a0 49 89 d4 49 89 f6 48 89 fb 49 bf 00 00 00 00 00 fc ff df e8 43 a0 b6 ff 48 89 5d a8 48 83 c3 30 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 25 17 f4 ff 48 8b 03 48 89 45 d0
RSP: 0018:ffffc90000967bd0 EFLAGS: 00010206
RAX: 0000000000000006 RBX: 0000000000000030 RCX: ffff88811e28cf00
RDX: 0000000000000000 RSI: ffff8881105c6018 RDI: 0000000000000000
RBP: ffffc90000967c30 R08: dffffc0000000000 R09: ffffed10220b8c19
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88811c4ceee0
R13: ffffc90000967cc8 R14: ffff8881105c6018 R15: dffffc0000000000
FS:  000055555608d480(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000000 CR3: 000000011e27b000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	89 4d a0             	mov    %ecx,-0x60(%rbp)
   3:	49 89 d4             	mov    %rdx,%r12
   6:	49 89 f6             	mov    %rsi,%r14
   9:	48 89 fb             	mov    %rdi,%rbx
   c:	49 bf 00 00 00 00 00 	movabs $0xdffffc0000000000,%r15
  13:	fc ff df
  16:	e8 43 a0 b6 ff       	call   0xffb6a05e
  1b:	48 89 5d a8          	mov    %rbx,-0x58(%rbp)
  1f:	48 83 c3 30          	add    $0x30,%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 25 17 f4 ff       	call   0xfff4175e
  39:	48 8b 03             	mov    (%rbx),%rax
  3c:	48 89 45 d0          	mov    %rax,-0x30(%rbp)

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/02/13 06:33 android13-5.10-lts fc10db4b1932 77b23aa1 .config strace log report syz C [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in vfs_link
2024/03/11 18:12 android13-5.10-lts dd976ecce2ce 6ee49f2e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in vfs_link
2024/02/13 06:05 android13-5.10-lts fc10db4b1932 77b23aa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 general protection fault in vfs_link
* Struck through repros no longer work on HEAD.