[Intel-wired-lan] [PATCH iwl-net] idpf: fix null-ptr-deref in idpf_features_check

[Salin, Samuel]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces at osuosl.org> On Behalf Of
> Pavan Kumar Linga
> Sent: Friday, April 11, 2025 9:01 AM
> To: intel-wired-lan at lists.osuosl.org
> Cc: netdev at vger.kernel.org; Linga, Pavan Kumar
> <pavan.kumar.linga at intel.com>; Chittim, Madhu
> <madhu.chittim at intel.com>
> Subject: [Intel-wired-lan] [PATCH iwl-net] idpf: fix null-ptr-deref in
> idpf_features_check
> 
> idpf_features_check is used to validate the TX packet. skb header length is
> compared with the hardware supported value received from the device
> control plane. The value is stored in the adapter structure and to access it,
> vport pointer is used. During reset all the vports are released and the vport
> pointer that the netdev private structure points to is NULL.
> 
> To avoid null-ptr-deref, store the max header length value in netdev private
> structure. This also helps to cache the value and avoid accessing adapter
> pointer in hot path.
> 
> BUG: kernel NULL pointer dereference, address: 0000000000000068 ...
> RIP: 0010:idpf_features_check+0x6d/0xe0 [idpf] Call Trace:
>  <TASK>
>  ? __die+0x23/0x70
>  ? page_fault_oops+0x154/0x520
>  ? exc_page_fault+0x76/0x190
>  ? asm_exc_page_fault+0x26/0x30
>  ? idpf_features_check+0x6d/0xe0 [idpf]
>  netif_skb_features+0x88/0x310
>  validate_xmit_skb+0x2a/0x2b0
>  validate_xmit_skb_list+0x4c/0x70
>  sch_direct_xmit+0x19d/0x3a0
>  __dev_queue_xmit+0xb74/0xe70
>  ...
> 
> Fixes: a251eee62133 ("idpf: add SRIOV support and other ndo_ops")
> Reviewed-by: Madhu Chititm <madhu.chittim at intel.com>
> Signed-off-by: Pavan Kumar Linga <pavan.kumar.linga at intel.com>
> ---
> 2.43.0

Tested-by: Samuel Salin <Samuel.salin at intel.com>