Re: [PATCH net 1/1] tcp: check skb is non-NULL in tcp_rto_delta_us()

[Eric Dumazet]

On Fri, Aug 23, 2024 at 5:34 AM Josh Hunt <johunt@xxxxxxxxxx> wrote:
>
> There have been multiple occassions where we have crashed in this path
> because packets_out suggested there were packets on the write or retransmit
> queues, but in fact there weren't leading to a NULL skb being dereferenced.
> While we should fix that root cause we should also just make sure the skb
> is not NULL before dereferencing it. Also add a warn once here to capture
> some information if/when the problem case is hit again.
>
> Signed-off-by: Josh Hunt <johunt@xxxxxxxxxx>

Hi Josh

We do not want a patch series of one patch, with the stack trace in
the cover letter.
Please send a standalone patch, with all the information in its changelog.

1) Add Neal Cardwell in the CC list.

2) Are you using TCP_REPAIR by any chance ?

3) Please double check your kernel has these fixes.

commit 1f85e6267caca44b30c54711652b0726fadbb131    tcp: do not send
empty skb from tcp_write_xmit()
commit 0c175da7b0378445f5ef53904247cfbfb87e0b78     tcp: prohibit
TCP_REPAIR_OPTIONS if data was already sent


Thanks.