[Intel-wired-lan] [PATCH] e1000e: do not panic on malformed rx_desc

[Neftin, Sasha]

On 10/1/2020 11:02, Neftin, Sasha wrote:
> Hello Tong,
> On 9/10/2020 11:22, Neftin, Sasha wrote:
>> On 9/8/2020 19:23, Tong Zhang wrote:
>>> length may be corrupted in rx_desc and lead to panic, so check the
>>> sanity before passing it to skb_put
>>>
>> Tong, what is scenario caused to skb panic? How it is happen on your 
>> system? Can you please share the test hint and your setup with us?
> Please, share your scenario and setup details (HW settings, BIOS, 
> Kernel, etc...). We would like to understand how exactly length 
> corruption is happen.
> 
Since no way to reproduce the problem, I would recommend dropping this 
patch.
> Thanks,
> Sasha
> 
>>> [  103.840572] skbuff: skb_over_panic: text:ffffffff8f432cc1 
>>> len:61585 put:61585 head:ffff88805642b800 data:ffff88805642b840 
>>> tail:0xf0d1 end:0x6c0 dev:e
>>> th0
>>> [  103.841283] ------------[ cut here ]------------
>>> [  103.841515] kernel BUG at net/core/skbuff.c:109!
>>> [  103.841749] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
>>> [  103.842063] CPU: 1 PID: 276 Comm: ping Tainted: G        W 5.8.0+ #4
>>> [  103.842857] RIP: 0010:skb_panic+0xc4/0xc6
>>> [  103.843022] Code: 89 f0 48 c7 c7 60 f2 3e 90 55 48 8b 74 24 18 4d 
>>> 89 f9 56 48 8b 54 24 18 4c 89 e6 52 48 8b 44 24 18 4c 89 ea 50 e8 01 
>>> c5 2a ff <0f>
>>> 0b 4c 8b 64 24 18 e8 c1 b4 48 ff 48 c7 c1 e0 fc 3e 90 44 89 ee
>>> [  103.843766] RSP: 0018:ffff88806d109c58 EFLAGS: 00010282
>>> [  103.843976] RAX: 000000000000008c RBX: ffff8880683407c0 RCX: 
>>> 0000000000000000
>>> [  103.844262] RDX: 1ffff1100da24c91 RSI: 0000000000000008 RDI: 
>>> ffffed100da2137e
>>> [  103.844548] RBP: ffff88806bdcc000 R08: 000000000000008c R09: 
>>> ffffed100da25cfb
>>> [  103.844834] R10: ffff88806d12e7d7 R11: ffffed100da25cfa R12: 
>>> ffffffff903efd20
>>> [  103.845123] R13: ffffffff8f432cc1 R14: 000000000000f091 R15: 
>>> ffff88805642b800
>>> [  103.845410] FS:  00007efcd06852c0(0000) GS:ffff88806d100000(0000) 
>>> knlGS:0000000000000000
>>> [  103.845734] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [  103.845966] CR2: 00007efccf94f8dc CR3: 0000000064810000 CR4: 
>>> 00000000000006e0
>>> [  103.846254] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 
>>> 0000000000000000
>>> [  103.846539] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 
>>> 0000000000000400
>>> [  103.846823] Call Trace:
>>> [  103.846925]  <IRQ>
>>> [  103.847013]  ? e1000_clean_rx_irq+0x311/0x630
>>> [  103.847190]  skb_put.cold+0x2b/0x4d
>>> [  103.847334]  e1000_clean_rx_irq+0x311/0x630
>>>
>>> Signed-off-by: Tong Zhang <ztong0001 at gmail.com>
>>> ---
>>>   drivers/net/ethernet/intel/e1000e/netdev.c | 4 ++++
>>>   1 file changed, 4 insertions(+)
>>>
>>> diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c 
>>> b/drivers/net/ethernet/intel/e1000e/netdev.c
>>> index 664e8ccc88d2..f12bd00b2dbf 100644
>>> --- a/drivers/net/ethernet/intel/e1000e/netdev.c
>>> +++ b/drivers/net/ethernet/intel/e1000e/netdev.c
>>> @@ -1047,6 +1047,10 @@ static bool e1000_clean_rx_irq(struct 
>>> e1000_ring *rx_ring, int *work_done,
>>>               }
>>>               /* else just continue with the old one */
>>>           }
>>> +        /* check length sanity */
>>> +        if (skb->tail + length > skb->end) {
>>> +            length = skb->end - skb->tail;
>>> +        }
>>>           /* end copybreak code */
>>>           skb_put(skb, length);
>>>
>>
>> _______________________________________________
>> Intel-wired-lan mailing list
>> Intel-wired-lan at osuosl.org
>> https://lists.osuosl.org/mailman/listinfo/intel-wired-lan
> 
Thanks,
Sasha