syzbot


general protection fault in unix_bind

Status: upstream: reported C repro on 2022/03/16 04:03
Reported-by: syzbot+ee97ac34229c41ff6d26@syzkaller.appspotmail.com
First crash: 1011d, last: 1011d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
UDF-fs: INFO Mounting volume 'LinuxUDF', timestamp 2020/09/19 18:44 (1000)
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
CPU: 0 PID: 8089 Comm: syz-executor408 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:unix_bind+0x5b1/0xa40 net/unix/af_unix.c:1088
Code: df 48 c1 ea 03 80 3c 02 00 0f 85 36 04 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 58 49 8d 7c 24 40 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 78 04 00 00 41 0f b6 44 24 40 48 c7 c7 80 77 f0
RSP: 0018:ffff8880a2eb7cc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff110145d6fa0 RCX: ffffffff8700df67
RDX: 0000000000000008 RSI: ffffffff8700df79 RDI: 0000000000000040
RBP: ffff8880a2eb7dc8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 00000000ac2ce7de R12: 0000000000000000
R13: 000000000000000d R14: ffff8880a19e75a8 R15: ffff8880a19e7080
FS:  00005555572df300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564c8839b068 CR3: 00000000aa836000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 __sys_bind+0x1e9/0x250 net/socket.c:1594
 __do_sys_bind net/socket.c:1605 [inline]
 __se_sys_bind net/socket.c:1603 [inline]
 __x64_sys_bind+0x6f/0xb0 net/socket.c:1603
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fde20a6a459
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffa10e2f88 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 0030656c69662f2e RCX: 00007fde20a6a459
RDX: 0000000000000056 RSI: 00000000200001c0 RDI: 0000000000000003
RBP: 00007fde20a29cf0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fde20a29d80
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 18c7f903bc39fafb ]---
RIP: 0010:unix_bind+0x5b1/0xa40 net/unix/af_unix.c:1088
Code: df 48 c1 ea 03 80 3c 02 00 0f 85 36 04 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 64 24 58 49 8d 7c 24 40 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 78 04 00 00 41 0f b6 44 24 40 48 c7 c7 80 77 f0
RSP: 0018:ffff8880a2eb7cc8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 1ffff110145d6fa0 RCX: ffffffff8700df67
RDX: 0000000000000008 RSI: ffffffff8700df79 RDI: 0000000000000040
RBP: ffff8880a2eb7dc8 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 00000000ac2ce7de R12: 0000000000000000
R13: 000000000000000d R14: ffff8880a19e75a8 R15: ffff8880a19e7080
FS:  00005555572df300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000564c8837a120 CR3: 00000000aa836000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	48 c1 ea 03          	shr    $0x3,%rdx
   4:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   8:	0f 85 36 04 00 00    	jne    0x444
   e:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  15:	fc ff df
  18:	4d 8b 64 24 58       	mov    0x58(%r12),%r12
  1d:	49 8d 7c 24 40       	lea    0x40(%r12),%rdi
  22:	48 89 fa             	mov    %rdi,%rdx
  25:	48 c1 ea 03          	shr    $0x3,%rdx
* 29:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2d:	0f 85 78 04 00 00    	jne    0x4ab
  33:	41 0f b6 44 24 40    	movzbl 0x40(%r12),%eax
  39:	48                   	rex.W
  3a:	c7                   	.byte 0xc7
  3b:	c7                   	.byte 0xc7
  3c:	80                   	.byte 0x80
  3d:	77 f0                	ja     0x2f

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/03/16 04:39 linux-4.19.y 3f8a27f9e27b 9e8eaa75 .config console log report syz C ci2-linux-4-19 general protection fault in unix_bind
2022/03/16 04:03 linux-4.19.y 3f8a27f9e27b 9e8eaa75 .config console log report info ci2-linux-4-19 general protection fault in unix_bind
* Struck through repros no longer work on HEAD.