Subject: Re: [PATCH net-next] ice: Fix NULL pointer dereference in switchdev

From: Simon Horman <[email-masked]>
Date: Mon, 4 Nov 2024 11:46:19 +0000

On Tue, Oct 29, 2024 at 10:42:59AM +0100, Wojciech Drewek wrote:
> Commit ("virtchnl: support queue rate limit and quanta size

It would be nice to include 12 characters of sha1 hash immediately
after "Commit".

> configuration") introduced new virtchnl ops:
> - get_qos_caps
> - cfg_q_bw
> - cfg_q_quanta
> 
> New ops were added to ice_virtchnl_dflt_ops but not to the
> ice_virtchnl_repr_ops. Because of that, if we get one of those
> messages in switchdev mode we end up with NULL pointer dereference:
> 
> [ 1199.794701] BUG: kernel NULL pointer dereference, address: 0000000000000000
> [ 1199.794804] Workqueue: ice ice_service_task [ice]
> [ 1199.794878] RIP: 0010:0x0
> [ 1199.795027] Call Trace:
> [ 1199.795033]  <TASK>
> [ 1199.795039]  ? __die+0x20/0x70
> [ 1199.795051]  ? page_fault_oops+0x140/0x520
> [ 1199.795064]  ? exc_page_fault+0x7e/0x270
> [ 1199.795074]  ? asm_exc_page_fault+0x22/0x30
> [ 1199.795086]  ice_vc_process_vf_msg+0x6e5/0xd30 [ice]
> [ 1199.795165]  __ice_clean_ctrlq+0x734/0x9d0 [ice]
> [ 1199.795207]  ice_service_task+0xccf/0x12b0 [ice]
> [ 1199.795248]  process_one_work+0x21a/0x620
> [ 1199.795260]  worker_thread+0x18d/0x330
> [ 1199.795269]  ? __pfx_worker_thread+0x10/0x10
> [ 1199.795279]  kthread+0xec/0x120
> [ 1199.795288]  ? __pfx_kthread+0x10/0x10
> [ 1199.795296]  ret_from_fork+0x2d/0x50
> [ 1199.795305]  ? __pfx_kthread+0x10/0x10
> [ 1199.795312]  ret_from_fork_asm+0x1a/0x30
> [ 1199.795323]  </TASK>

It seems that the cited commit is present in net-next but not Linus's tree.
But, regardless, I think a Fixes tag is warranted.

> 
> Reviewed-by: Przemek Kitszel <[email-masked]>
> Reviewed-by: Michal Swiatkowski <[email-masked]>
> Signed-off-by: Wojciech Drewek <[email-masked]>

The fix itself looks good to me, thanks.

Reviewed-by: Simon Horman <[email-masked]>

...