syzbot


general protection fault in inet_csk_accept

Status: fixed on 2022/03/08 16:11
Reported-by: syzbot+e4d843bb96a9431e6331@syzkaller.appspotmail.com
Fix commit: b0cdc5dbcf2b mptcp: never allow the PM to close a listener subflow
First crash: 241d, last: 241d

Cause bisection: introduced by (bisect log) :
commit 7f700334be9aeb91d5d86ef9ad2d901b9b453e9b
Author: Eric Dumazet <edumazet@google.com>
Date: Mon Mar 29 18:39:51 2021 +0000

  ip6_gre: proper dev_{hold|put} in ndo_[un]init methods

Crash: unregister_netdevice: waiting for DEV to become free (log)
Repro: C syz .config
Patch testing requests:
Created Duration User Patch Repo Result
2021/12/10 18:26 15m pabeni@redhat.com patch net OK
2021/12/10 12:27 15m pabeni@redhat.com patch net OK

Sample crash report:
general protection fault, probably for non-canonical address 0xdffffc0000000003: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000018-0x000000000000001f]
CPU: 1 PID: 6550 Comm: syz-executor122 Not tainted 5.16.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:__lock_acquire+0xd7d/0x54a0 kernel/locking/lockdep.c:4897
Code: 0f 0e 41 be 01 00 00 00 0f 86 c8 00 00 00 89 05 69 cc 0f 0e e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 f3 2f 00 00 48 81 3b 20 75 17 8f 0f 84 52 f3 ff
RSP: 0018:ffffc90001f2f818 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 000000000000000a R12: 0000000000000000
R13: ffff88801b98d700 R14: 0000000000000000 R15: 0000000000000001
FS:  00007f177cd3d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f177cd1b268 CR3: 000000001dd55000 CR4: 0000000000350ee0
Call Trace:
 <TASK>
 lock_acquire kernel/locking/lockdep.c:5637 [inline]
 lock_acquire+0x1ab/0x510 kernel/locking/lockdep.c:5602
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x39/0x50 kernel/locking/spinlock.c:162
 finish_wait+0xc0/0x270 kernel/sched/wait.c:400
 inet_csk_wait_for_connect net/ipv4/inet_connection_sock.c:464 [inline]
 inet_csk_accept+0x7de/0x9d0 net/ipv4/inet_connection_sock.c:497
 mptcp_accept+0xe5/0x500 net/mptcp/protocol.c:2865
 inet_accept+0xe4/0x7b0 net/ipv4/af_inet.c:739
 mptcp_stream_accept+0x2e7/0x10e0 net/mptcp/protocol.c:3345
 do_accept+0x382/0x510 net/socket.c:1773
 __sys_accept4_file+0x7e/0xe0 net/socket.c:1816
 __sys_accept4+0xb0/0x100 net/socket.c:1846
 __do_sys_accept net/socket.c:1864 [inline]
 __se_sys_accept net/socket.c:1861 [inline]
 __x64_sys_accept+0x71/0xb0 net/socket.c:1861
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7f177cd8b8e9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 b1 14 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f177cd3d308 EFLAGS: 00000246 ORIG_RAX: 000000000000002b
RAX: ffffffffffffffda RBX: 00007f177ce13408 RCX: 00007f177cd8b8e9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f177ce13400 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f177ce1340c
R13: 00007f177cde1004 R14: 6d705f706374706d R15: 0000000000022000
 </TASK>
Modules linked in:
---[ end trace 77ed64e4985d56c9 ]---
RIP: 0010:__lock_acquire+0xd7d/0x54a0 kernel/locking/lockdep.c:4897
Code: 0f 0e 41 be 01 00 00 00 0f 86 c8 00 00 00 89 05 69 cc 0f 0e e9 bd 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 f3 2f 00 00 48 81 3b 20 75 17 8f 0f 84 52 f3 ff
RSP: 0018:ffffc90001f2f818 EFLAGS: 00010016
RAX: dffffc0000000000 RBX: 0000000000000018 RCX: 0000000000000000
RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: 000000000000000a R12: 0000000000000000
R13: ffff88801b98d700 R14: 0000000000000000 R15: 0000000000000001
FS:  00007f177cd3d700(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f177cd1b268 CR3: 000000001dd55000 CR4: 0000000000350ee0
----------------
Code disassembly (best guess):
   0:	0f 0e                	femms
   2:	41 be 01 00 00 00    	mov    $0x1,%r14d
   8:	0f 86 c8 00 00 00    	jbe    0xd6
   e:	89 05 69 cc 0f 0e    	mov    %eax,0xe0fcc69(%rip)        # 0xe0fcc7d
  14:	e9 bd 00 00 00       	jmpq   0xd6
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 da             	mov    %rbx,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 f3 2f 00 00    	jne    0x3027
  34:	48 81 3b 20 75 17 8f 	cmpq   $0xffffffff8f177520,(%rbx)
  3b:	0f                   	.byte 0xf
  3c:	84 52 f3             	test   %dl,-0xd(%rdx)
  3f:	ff                   	.byte 0xff

Crashes (8):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2021/12/08 22:52 upstream 2a987e65025e a4a2a501 .config log report syz C general protection fault in inet_csk_accept
ci-upstream-net-this-kasan-gce 2021/12/09 00:01 net b5bd95d17102 a4a2a501 .config log report syz C general protection fault in inet_csk_accept
ci-upstream-net-this-kasan-gce 2021/12/08 23:41 net b5bd95d17102 a4a2a501 .config log report syz C general protection fault in inet_csk_accept
ci-upstream-net-kasan-gce 2021/12/08 23:33 net-next 150791442e7c a4a2a501 .config log report syz C general protection fault in inet_csk_accept
ci-upstream-net-kasan-gce 2021/12/08 22:52 net-next 150791442e7c a4a2a501 .config log report syz C general protection fault in inet_csk_accept
ci-upstream-kasan-gce-root 2021/12/08 22:31 upstream 2a987e65025e a4a2a501 .config log report info general protection fault in inet_csk_accept
ci-upstream-net-kasan-gce 2021/12/09 11:11 net-next 3a262c71d3e8 a4a2a501 .config log report info general protection fault in inet_csk_accept
ci-upstream-net-kasan-gce 2021/12/08 22:30 net-next 150791442e7c a4a2a501 .config log report info general protection fault in inet_csk_accept