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Date:   Tue, 27 Sep 2022 07:14:49 -0700
From:   Jakub Kicinski <kuba@kernel.org>
To:     syzbot <syzbot+c5ce866a8d30f4be0651@syzkaller.appspotmail.com>
Cc:     bpf@vger.kernel.org, davem@davemloft.net, edumazet@google.com,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
        pabeni@redhat.com, syzkaller-bugs@googlegroups.com,
        Jon Maloy <jmaloy@redhat.com>,
        Ying Xue <ying.xue@windriver.com>,
        tipc-discussion@lists.sourceforge.net
Subject: Re: [syzbot] general protection fault in kernel_accept (5)
Message-ID: <20220927071449.67a2b0a0@kernel.org>
In-Reply-To: <0000000000006d989105e9a4b916@google.com>
References: <0000000000006d989105e9a4b916@google.com>
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Adding TIPC

On Tue, 27 Sep 2022 01:49:38 -0700 syzbot wrote:
> Hello,
> 
> syzbot found the following issue on:
> 
> HEAD commit:    bf682942cd26 Merge tag 'scsi-fixes' of git://git.kernel.or..
> git tree:       upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=117fc3ac880000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=7db7ad17eb14cb7
> dashboard link: https://syzkaller.appspot.com/bug?extid=c5ce866a8d30f4be0651
> compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
> 
> Unfortunately, I don't have any reproducer for this issue yet.
> 
> IMPORTANT: if you fix the issue, please add the following tag to the commit:
> Reported-by: syzbot+c5ce866a8d30f4be0651@syzkaller.appspotmail.com
> 
> general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
> KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
> CPU: 3 PID: 12841 Comm: kworker/u16:2 Not tainted 6.0.0-rc6-syzkaller-00210-gbf682942cd26 #0
> Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
> Workqueue: tipc_rcv tipc_topsrv_accept
> RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487
> Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 e3 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 20 48 8d 7b 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ee 00 00 00 48 8b 7b 08 e8 a0 36 1c fa e8 8b ff
> RSP: 0018:ffffc9000494fc28 EFLAGS: 00010202
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: 0000000000000001 RSI: ffffffff874c37b2 RDI: 0000000000000008
> RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000449 R12: 0000000000000000
> R13: ffff888027a7b980 R14: ffff888028bc08e0 R15: 1ffff92000929f90
> FS:  0000000000000000(0000) GS:ffff88802cb00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 00007fa6e1a8c920 CR3: 000000004bba0000 CR4: 0000000000150ee0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> Call Trace:
>  <TASK>
>  tipc_topsrv_accept+0x197/0x280 net/tipc/topsrv.c:460
>  process_one_work+0x991/0x1610 kernel/workqueue.c:2289
>  worker_thread+0x665/0x1080 kernel/workqueue.c:2436
>  kthread+0x2e4/0x3a0 kernel/kthread.c:376
>  ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
>  </TASK>
> Modules linked in:
> ---[ end trace 0000000000000000 ]---
> RIP: 0010:kernel_accept+0x22d/0x350 net/socket.c:3487
> Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 e3 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8b 5b 20 48 8d 7b 08 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 ee 00 00 00 48 8b 7b 08 e8 a0 36 1c fa e8 8b ff
> RSP: 0018:ffffc9000494fc28 EFLAGS: 00010202
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
> RDX: 0000000000000001 RSI: ffffffff874c37b2 RDI: 0000000000000008
> RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000449 R12: 0000000000000000
> R13: ffff888027a7b980 R14: ffff888028bc08e0 R15: 1ffff92000929f90
> FS:  0000000000000000(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000c0154d8000 CR3: 000000006fb4b000 CR4: 0000000000150ee0
> DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
> DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
> ----------------
> Code disassembly (best guess):
>    0:	48 89 fa             	mov    %rdi,%rdx
>    3:	48 c1 ea 03          	shr    $0x3,%rdx
>    7:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
>    b:	0f 85 e3 00 00 00    	jne    0xf4
>   11:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
>   18:	fc ff df
>   1b:	48 8b 5b 20          	mov    0x20(%rbx),%rbx
>   1f:	48 8d 7b 08          	lea    0x8(%rbx),%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 ee 00 00 00    	jne    0x122
>   34:	48 8b 7b 08          	mov    0x8(%rbx),%rdi
>   38:	e8 a0 36 1c fa       	callq  0xfa1c36dd
>   3d:	e8                   	.byte 0xe8
>   3e:	8b ff                	mov    %edi,%edi
> 
> 
> ---
> This report is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this issue. See:
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