Hi Eric,
It seems that your patch fixes the issue, I'm not seeing the report any more.
Tested-by: Andrey Konovalov <andreyk...@google.com>
Thanks!
On Thu, Nov 3, 2016 at 4:39 PM, Eric Dumazet <eduma...@google.com> wrote:
> On Wed, Nov 2, 2016 at 2:14 PM, Andrey Konovalov <andreyk...@google.com>
> wrote:
>> Hi,
>>
>> I've got the following error report while running the syzkaller fuzzer:
>>
>> BUG: unable to handle kernel NULL pointer dereference at (null)
>> IP: [< (null)>] (null)
>> PGD 66b6f067 [ 102.549865] PUD 66c6e067
>> PMD 0 [ 102.549865]
>> Oops: 0010 [#1] SMP KASAN
>> Modules linked in:
>> CPU: 0 PID: 4143 Comm: a.out Not tainted 4.9.0-rc3+ #336
>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
>> task: ffff880066b1c200 task.stack: ffff880065b58000
>> RIP: 0010:[<0000000000000000>] [< (null)>] (null)
>> RSP: 0018:ffff880065b5fbc0 EFLAGS: 00010246
>> RAX: ffff880066b1c200 RBX: ffff88006873864a RCX: 0000000000000000
>> RDX: 0000000000000001 RSI: ffff880068738640 RDI: ffff880063bd3200
>> RBP: ffff880065b5fd20 R08: 1ffff1000c77a713 R09: dffffc0000000000
>> R10: ffffffff844fc800 R11: 1ffff1000d0e70c9 R12: ffffffff84e7e040
>> R13: ffff880068738640 R14: ffff880063bd3200 R15: ffffffff86836380
>> FS: 00007f40b7acf700(0000) GS:ffff88006cc00000(0000) knlGS:0000000000000000
>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>> CR2: 0000000000000000 CR3: 000000006bb28000 CR4: 00000000000006f0
>> Stack:
>> ffffffff83099988 ffffffff8479f7e8 ffffffff81208580 1ffff1000000000c
>> 0000000041b58ab3 ffffffff8479f7e8 ffffffff81208580 ffffffff812506ed
>> 0000000000000007 ffff880065b5fc18 ffffffff812506ed ffff880065b5fcd0
>> Call Trace:
>> [<ffffffff832cf4fc>] inet6_bind+0x8ec/0x1020 net/ipv6/af_inet6.c:384
>> [<ffffffff82b7033c>] SYSC_bind+0x1ec/0x250 net/socket.c:1367
>> [<ffffffff82b72ae4>] SyS_bind+0x24/0x30 net/socket.c:1353
>> [<ffffffff83fc0401>] entry_SYSCALL_64_fastpath+0x1f/0xc2
>> arch/x86/entry/entry_64.S:209
>> Code: Bad RIP value.
>> RIP [< (null)>] (null)
>> RSP <ffff880065b5fbc0>
>> CR2: 0000000000000000
>> ---[ end trace b5ec698ae4926a97 ]---
>> Kernel panic - not syncing: Fatal exception in interrupt
>> Kernel Offset: disabled
>> ---[ end Kernel panic - not syncing: Fatal exception in interrupt
>>
>> On commit 0c183d92b20b5c84ca655b45ef57b3318b83eb9e (Oct 31).
>>
>> I'm able to reproduce it with the attached program by running it as:
>> $ gcc -lpthread inet6-bind-poc.c
>> $ while true; do ./a.out; done
>>
>> Thanks!
>
> Looks like this patch should fix it ?
>
> Thanks !
>
> diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
> index 3828f94b234c..95353bdbfa7b 100644
> --- a/net/dccp/ipv6.c
> +++ b/net/dccp/ipv6.c
> @@ -956,6 +956,7 @@ static const struct inet_connection_sock_af_ops
> dccp_ipv6_mapped = {
> .getsockopt = ipv6_getsockopt,
> .addr2sockaddr = inet6_csk_addr2sockaddr,
> .sockaddr_len = sizeof(struct sockaddr_in6),
> + .bind_conflict = inet6_csk_bind_conflict,
> #ifdef CONFIG_COMPAT
> .compat_setsockopt = compat_ipv6_setsockopt,
> .compat_getsockopt = compat_ipv6_getsockopt,
