syzbot


general protection fault in skb_clone

Status: upstream: reported C repro on 2022/10/17 02:33
Reported-by: syzbot+0a20173d50b1d0a8dc18@syzkaller.appspotmail.com
First crash: 494d, last: 361d
Similar bugs (7)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in skb_clone syz 3 2382d 2381d 3/26 fixed on 2017/10/24 19:00
upstream BUG: unable to handle kernel paging request in skb_clone net 2 924d 969d 0/26 closed as invalid on 2021/10/04 21:36
upstream general protection fault in skb_clone (3) net 44 1366d 1368d 15/26 fixed on 2020/07/17 17:58
linux-4.19 general protection fault in skb_clone C error 2 494d 803d 0/1 upstream: reported C repro on 2021/12/12 07:38
upstream general protection fault in skb_clone (4) net C unreliable 41 506d 803d 0/26 closed as invalid on 2022/10/12 18:15
upstream general protection fault in skb_clone (2) hams 1 1550d 1547d 0/26 auto-closed as invalid on 2020/03/25 12:28
upstream general protection fault in skb_clone (5) net C done 7 479d 497d 22/26 fixed on 2023/02/24 13:50
Fix bisection attempts (3)
Created Duration User Patch Repo Result
2023/02/27 13:37 27m bisect fix linux-4.14.y job log (0) log
2023/01/26 04:27 26m bisect fix linux-4.14.y job log (0) log
2022/11/17 04:26 25m bisect fix linux-4.14.y job log (0) log

Sample crash report:
RBP: 00007fffe50445f0 R08: 0000000000000000 R09: 0000000000000001
R10: 00007fffe5044367 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fffe5044610 R14: 00007fffe5044600 R15: 00007fffe50445dc
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: 1 PID: 8203 Comm: syz-executor246 Not tainted 4.14.295-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
task: ffff8880aff623c0 task.stack: ffff8880b00b8000
RIP: 0010:skb_clone+0xd8/0x9a0 net/core/skbuff.c:1283
RSP: 0018:ffff8880b00bf6b0 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000011 RSI: 0000000001080020 RDI: 0000000000000000
RBP: 000000000000008e R08: 0000000000000140 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000001080020
R13: ffff8880a5191f00 R14: ffff8880ab9ab280 R15: dffffc0000000000
FS:  00005555557a3300(0000) GS:ffff8880ba500000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f0bd7160ed0 CR3: 000000009e7f7000 CR4: 00000000003406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 frame_get_stripped_skb net/hsr/hsr_forward.c:127 [inline]
 hsr_forward_do net/hsr/hsr_forward.c:285 [inline]
 hsr_forward_skb+0xdbb/0x19c0 net/hsr/hsr_forward.c:373
 hsr_handle_frame+0x2e0/0x550 net/hsr/hsr_slave.c:50
 __netif_receive_skb_core+0x730/0x2a30 net/core/dev.c:4428
 __netif_receive_skb+0x27/0x1a0 net/core/dev.c:4512
 netif_receive_skb_internal+0xd7/0x580 net/core/dev.c:4585
 tun_rx_batched.isra.0+0x45c/0x710 drivers/net/tun.c:1234
 tun_get_user+0x12ae/0x4710 drivers/net/tun.c:1594
 tun_chr_write_iter+0xe8/0x1f0 drivers/net/tun.c:1625
 call_write_iter include/linux/fs.h:1780 [inline]
 new_sync_write fs/read_write.c:469 [inline]
 __vfs_write+0x44c/0x630 fs/read_write.c:482
 vfs_write+0x17f/0x4d0 fs/read_write.c:544
 SYSC_write fs/read_write.c:590 [inline]
 SyS_write+0xf2/0x210 fs/read_write.c:582
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x7f0bd70ece83
RSP: 002b:00007fffe50445c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f0bd70ece83
RDX: 0000000000000036 RSI: 0000000020000640 RDI: 00000000000000c8
RBP: 00007fffe50445f0 R08: 0000000000000000 R09: 0000000000000001
R10: 00007fffe5044367 R11: 0000000000000246 R12: 0000000000000003
R13: 00007fffe5044610 R14: 00007fffe5044600 R15: 00007fffe50445dc
Code: be 07 00 00 f6 45 03 08 0f 85 ff 05 00 00 e8 60 a9 95 fb 48 8d ab 8e 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 ea 48 c1 ea 03 <0f> b6 04 02 48 89 ea 83 e2 07 38 d0 7f 08 84 c0 0f 85 9f 07 00 
RIP: skb_clone+0xd8/0x9a0 net/core/skbuff.c:1283 RSP: ffff8880b00bf6b0
---[ end trace 8e3080fb750ee8ac ]---
----------------
Code disassembly (best guess):
   0:	be 07 00 00 f6       	mov    $0xf6000007,%esi
   5:	45 03 08             	add    (%r8),%r9d
   8:	0f 85 ff 05 00 00    	jne    0x60d
   e:	e8 60 a9 95 fb       	callq  0xfb95a973
  13:	48 8d ab 8e 00 00 00 	lea    0x8e(%rbx),%rbp
  1a:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  21:	fc ff df
  24:	48 89 ea             	mov    %rbp,%rdx
  27:	48 c1 ea 03          	shr    $0x3,%rdx
* 2b:	0f b6 04 02          	movzbl (%rdx,%rax,1),%eax <-- trapping instruction
  2f:	48 89 ea             	mov    %rbp,%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                   	.byte 0x85
  3d:	9f                   	lahf
  3e:	07                   	(bad)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/10/17 02:32 linux-4.14.y 9d5c0b3a8e1a 67cb024c .config console log report syz C [disk image] [vmlinux] ci2-linux-4-14 general protection fault in skb_clone
* Struck through repros no longer work on HEAD.