Re: [PATCH net] net/mlx5e: Fix NULL deref in PTP TX timestamp recovery warn

[Carolina Jubran <cjubran@nvidia.com>]

On 15/10/2026 11:09, netdev-bot+sinfo@kernel.org wrote:
> Hi!
>
> This is an automated message. This series looks like a fix, but its
> commit messages seem to be missing some information:
>
>   - How the issue was discovered, e.g. hit in production, hit during
>     development, syzbot report, manual code inspection, LLM or static
>     analysis tool scan.
>
>   - Whether the issue was actually triggered, or is only theoretical
>     (e.g. found by code inspection). If it was triggered please include
>     the symptoms, like the stack trace or error messages.
>
> Please do not repost the series just to address the above. Instead,
> reply to this email with the missing information, so that reviewers
> can take it into account. If the series needs another revision for
> other reasons, please include the information in the commit messages
> then.
>
> The evaluation is done by an LLM so it may be wrong, if you think
> that is the case please reply and explain.


Hi,

The issue was observed during our internal regression testing.

The kernel reported:

BUG: unable to handle page fault for address: 0000000000002ea8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 1a9bfc067 P4D 1a9bfc067 PUD 1a9bfd067 PMD 0
Oops: 0000 [#1] PREEMPT SMP NOPTI
CPU: 0 PID: 0 Comm: swapper/0 Tainted: G           OE
RIP: 0010:mlx5e_skb_cb_hwtstamp_handler+0x10c/0x140 [mlx5_core]
RAX: 0000000000000000
CR2: 0000000000002ea8
Call Trace:
   mlx5e_ptp_poll_ts_cq+0x228/0x5b0 [mlx5_core]
   mlx5e_ptp_napi_poll+0xad/0x380 [mlx5_core]
   ? mlx5e_napi_poll+0x750/0x7e0 [mlx5_core]
   __napi_poll+0x30/0x200
   net_rx_action+0x181/0x2e0
   handle_softirqs+0xdb/0x340
   __irq_exit_rcu+0xd9/0x100
   irq_exit_rcu+0xe/0x20
   common_interrupt+0xa4/0xb0

So far, the issue has only been observed during our regression testing,
and I am still working on reproducing it reliably.

Thanks,
Carolina