Re: [ixgbe] Crash when running an XDP program

["Toke Høiland-Jørgensen" <toke@redhat.com>]

Maciej Fijalkowski <maciej.fijalkowski@intel.com> writes:

> On Wed, Feb 12, 2025 at 01:33:09PM +0100, Toke Høiland-Jørgensen wrote:
>> Hi folks,
>> 
>> Our LNST testing team uncovered a crash in ixgbe when running an XDP
>> program, see this report:
>> https://bugzilla.redhat.com/show_bug.cgi?id=2343204
>> 
>> From looking at the code, it seems to me that the culprit is this commit:
>> 
>> c824125cbb18 ("ixgbe: Fix passing 0 to ERR_PTR in ixgbe_run_xdp()")
>> 
>> after that commit, the IS_ERR(skb) check in ixgbe_put_rx_buffer() no
>> longer triggers, and that function tries to dereference a NULL skb
>> pointer after an XDP program dropped the frame.
>> 
>> Could you please fix this?
>
> Hi Toke,
>
> https://lore.kernel.org/netdev/20250211214343.4092496-5-anthony.l.nguyen@intel.com/
>
> can you see if this fixes it?

Ah! I went looking in the -net and -net-next git trees to see if you'd
already fixed this, but didn't check the list. Thanks for the pointer,
will see if we can get this tested.

> Validation in our company has always been a mystery to me, sorry for this
> inconvenience and that we were bad at reviewing :<

No worries, bugs happen; thankfully we caught it early. Also mostly
meant it as a nudge to try to give XDP testing a more prominent spot :)

-Toke