general protection fault in vgem_fence_attach_ioctl

Status: upstream: reported syz repro on 2020/11/03 17:27
Reported-by: syzbot+1b5240d1111ab4dadb95@syzkaller.appspotmail.com
First crash: 2118d, last: 1393d
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 general protection fault in vgem_fence_attach_ioctl 2 syz, C error 28 1582d 2183d 0/1 upstream: reported C repro on 2020/08/30 20:35
▶ ▼ Fix bisection attempts (22)
Created Duration User Patch Repo Result
2023/02/03 12:16 0m bisect fix linux-4.14.y error job log
2022/10/29 08:17 29m bisect fix linux-4.14.y OK (0) job log log
2022/09/11 12:16 19m bisect fix linux-4.14.y OK (0) job log log
2022/08/12 11:50 25m bisect fix linux-4.14.y OK (0) job log log
2022/07/13 11:22 27m bisect fix linux-4.14.y OK (0) job log log
2022/06/13 11:00 21m bisect fix linux-4.14.y OK (0) job log log
2022/04/29 22:05 23m bisect fix linux-4.14.y OK (0) job log log
2022/03/30 21:34 30m bisect fix linux-4.14.y OK (0) job log log
2022/02/28 19:55 29m bisect fix linux-4.14.y OK (0) job log log
2022/01/29 19:32 22m bisect fix linux-4.14.y OK (0) job log log
2021/12/30 19:01 31m bisect fix linux-4.14.y OK (0) job log log
2021/11/30 18:02 25m bisect fix linux-4.14.y OK (0) job log log
2021/10/31 17:06 27m bisect fix linux-4.14.y OK (0) job log log
2021/09/25 11:34 24m bisect fix linux-4.14.y OK (0) job log log
2021/08/26 11:12 22m bisect fix linux-4.14.y OK (0) job log log
2021/07/27 10:50 21m bisect fix linux-4.14.y OK (0) job log log
2021/06/16 08:11 25m bisect fix linux-4.14.y OK (0) job log log
2021/05/05 23:19 24m bisect fix linux-4.14.y OK (0) job log log
2021/03/26 22:32 20m bisect fix linux-4.14.y OK (0) job log log
2021/02/24 16:48 22m bisect fix linux-4.14.y OK (0) job log log
2021/02/03 13:17 1m bisect fix linux-4.14.y error job log
2021/01/04 12:55 22m bisect fix linux-4.14.y OK (0) job log log

Sample crash report:
Bluetooth: hci0 command 0x0419 tx timeout
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: 20750 Comm: syz-executor.0 Not tainted 4.14.277-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff888097b54580 task.stack: ffff88809a398000
RIP: 0010:vgem_fence_attach_ioctl+0x2f8/0x6e0 drivers/gpu/drm/vgem/vgem_fence.c:184
RSP: 0018:ffff88809a39fbb0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffff88809a39fcd0 RCX: 0000000000000000
RDX: 000000000000001c RSI: 0000000000000001 RDI: 00000000000000e0
RBP: ffff8880a9022d00 R08: ffffffff8bfb9d88 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809e5e7580
R13: 1ffff11013473f78 R14: ffff88809a39fcd4 R15: 0000000000000000
FS:  00007feac2dd1700(0000) GS:ffff8880ba400000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007feac2d8f718 CR3: 00000000a8974000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 drm_ioctl_kernel+0x14c/0x200 drivers/gpu/drm/drm_ioctl.c:737
 drm_ioctl+0x42e/0x890 drivers/gpu/drm/drm_ioctl.c:840
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x75a/0xff0 fs/ioctl.c:684
 SYSC_ioctl fs/ioctl.c:701 [inline]
 SyS_ioctl+0x7f/0xb0 fs/ioctl.c:692
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7feac365c0e9
RSP: 002b:00007feac2dd1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007feac376ef60 RCX: 00007feac365c0e9
RDX: 0000000020000040 RSI: 00000000c0106441 RDI: 0000000000000003
RBP: 00007feac36b608d R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff55231fcf R14: 00007feac2dd1300 R15: 0000000000022000
Code: ea 03 80 3c 02 00 0f 85 a2 03 00 00 4c 8b bd 18 01 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bf e0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 86 03 00 00 4c 89 f2 4d 8b bf e0 00 00 00 48 
RIP: vgem_fence_attach_ioctl+0x2f8/0x6e0 drivers/gpu/drm/vgem/vgem_fence.c:184 RSP: ffff88809a39fbb0
---[ end trace 819c1f5a16448241 ]---
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	03 80 3c 02 00 0f    	add    0xf00023c(%rax),%eax
   6:	85 a2 03 00 00 4c    	test   %esp,0x4c000003(%rdx)
   c:	8b bd 18 01 00 00    	mov    0x118(%rbp),%edi
  12:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  19:	fc ff df
  1c:	49 8d bf e0 00 00 00 	lea    0xe0(%r15),%rdi
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 86 03 00 00    	jne    0x3ba
  34:	4c 89 f2             	mov    %r14,%rdx
  37:	4d 8b bf e0 00 00 00 	mov    0xe0(%r15),%r15
  3e:	48                   	rex.W

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/05/03 13:04 linux-4.14.y e3a56aaade89 2df221f6 .config console log report syz ci2-linux-4-14 general protection fault in vgem_fence_attach_ioctl
2021/06/27 10:50 linux-4.14.y cfb41ef9deb1 9d2ab5df .config console log report syz ci2-linux-4-14 general protection fault in vgem_fence_attach_ioctl
2021/05/17 08:10 linux-4.14.y 7d7d1c0ab3eb f54a5c09 .config console log report syz ci2-linux-4-14 general protection fault in vgem_fence_attach_ioctl
2020/12/05 12:55 linux-4.14.y c196b3a9c83a 0ef84591 .config console log report syz ci2-linux-4-14
2022/05/14 11:00 linux-4.14.y 569d1abf9402 744a39e2 .config console log report info ci2-linux-4-14 general protection fault in vgem_fence_attach_ioctl
2021/04/05 23:19 linux-4.14.y bd634aa64163 6a81331a .config console log report info ci2-linux-4-14 general protection fault in vgem_fence_attach_ioctl
2020/11/03 17:26 linux-4.14.y 2b7915014161 cba33199 .config console log report info ci2-linux-4-14
* Struck through repros no longer work on HEAD.