Re: general protection fault in __lock_acquire (2)

[Eric Biggers]

On Thu, Nov 02, 2017 at 03:55:00AM -0700, syzbot wrote:
> Hello,
> 
> syzkaller hit the following crash on
> fa8785e862ef644f742558f1a8c91eca6f3f0004
> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
> 
> 
> 
> 
> R10: 0000000020869000 R11: 0000000000000246 R12: 00000000004a96f0
> R13: 0000000000000000 R14: 00007fe1d40269c8 R15: 00007fe1d4026b38
> Subscriber rejected, no memory
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] SMP KASAN
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Modules linked in:
> CPU: 3 PID: 16314 Comm: syz-executor6 Not tainted 4.14.0-rc7-next-20171102+
> #9
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> task: ffff88003d54a000 task.stack: ffff880038f70000
> RIP: 0010:__lock_acquire+0xdac/0x4770 kernel/locking/lockdep.c:3378
> RSP: 0018:ffff880038f77328 EFLAGS: 00010002
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: 0000000000000004 RSI: 0000000000000000 RDI: ffffffff85ecb380
> RBP: ffff880038f77830 R08: 0000000000000001 R09: 0000000000000000
> R10: 0000000000000000 R11: ffffffff8744cca0 R12: ffff88003d54a000
> R13: 0000000000000000 R14: 0000000000000001 R15: 0000000000000020
> FS:  00007fe1d4027700(0000) GS:ffff88006df00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fbbb18db000 CR3: 000000006a863000 CR4: 00000000000026e0
> Call Trace:
>  lock_acquire+0x1d5/0x580 kernel/locking/lockdep.c:4004
>  __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
>  _raw_spin_lock_bh+0x31/0x40 kernel/locking/spinlock.c:173
>  spin_lock_bh include/linux/spinlock.h:319 [inline]
>  tipc_subscrb_subscrp_delete+0x8f/0x480 net/tipc/subscr.c:201
>  tipc_subscrb_delete net/tipc/subscr.c:238 [inline]
>  tipc_subscrb_release_cb+0x17/0x30 net/tipc/subscr.c:316
>  tipc_close_conn+0x171/0x270 net/tipc/server.c:204
>  tipc_topsrv_kern_subscr+0x724/0x810 net/tipc/server.c:514
>  tipc_group_create+0x702/0x9c0 net/tipc/group.c:184
>  tipc_sk_join net/tipc/socket.c:2747 [inline]
>  tipc_setsockopt+0x249/0xc10 net/tipc/socket.c:2861
>  SYSC_setsockopt net/socket.c:1851 [inline]
>  SyS_setsockopt+0x189/0x360 net/socket.c:1830
>  entry_SYSCALL_64_fastpath+0x1f/0xbe
> RIP: 0033:0x447c89
> RSP: 002b:00007fe1d4026bd8 EFLAGS: 00000246 ORIG_RAX: 0000000000000036
> RAX: ffffffffffffffda RBX: 00007fe1d40276cc RCX: 0000000000447c89
> RDX: 0000000000000087 RSI: 000000000000010f RDI: 0000000000000013
> RBP: 0000000000000086 R08: 0000000000000010 R09: 0000000000000000
> R10: 0000000020869000 R11: 0000000000000246 R12: 00000000004a96f0
> R13: 0000000000000000 R14: 00007fe1d40269c8 R15: 00007fe1d4026b38
> Code: e9 03 f3 48 ab 48 81 c4 e0 04 00 00 44 89 f0 5b 41 5c 41 5d 41 5e 41
> 5f 5d c3 4c 89 fa 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80> 3c 02 00 0f
> 85 bf 33 00 00 49 81 3f 80 87 87 86 41 be 00 00
> RIP: __lock_acquire+0xdac/0x4770 kernel/locking/lockdep.c:3378 RSP:
> ffff880038f77328
> ---[ end trace 61ded41cffc497c5 ]---
> Kernel panic - not syncing: Fatal exception in interrupt
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Kernel Offset: disabled
> Rebooting in 86400 seconds..
> 
> 
> ---
> This bug is generated by a dumb bot. It may contain errors.
> See https://goo.gl/tpsmEJ for details.
> Direct all questions to syzkaller@xxxxxxxxxxxxxxxxx
> Please credit me with: Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx>
> 
> syzbot will keep track of this bug report.
> Once a fix for this bug is committed, please reply to this email with:
> #syz fix: exact-commit-title

No longer occurring, seems to have been fixed by:

#syz fix: tipc: fix a null pointer deref on error path