> -----Original Message-----
> From: Intel-wired-lan <[email protected]> On Behalf Of
> Simon Horman
> Sent: Tuesday, October 14, 2025 2:25 AM
> To: Tantilov, Emil S <[email protected]>
> Cc: [email protected]; [email protected]; Kitszel,
> Przemyslaw <[email protected]>; Nguyen, Anthony L
> <[email protected]>; [email protected];
> [email protected]; [email protected]; [email protected];
> [email protected]; [email protected]; [email protected]; Hay, Joshua
> A <[email protected]>; Chittim, Madhu <[email protected]>
> Subject: Re: [Intel-wired-lan] [PATCH iwl-net] idpf: fix possible vport_config
> NULL pointer deref in remove
>
> On Mon, Oct 13, 2025 at 08:08:24AM -0700, Emil Tantilov wrote:
> > Attempting to remove the driver will cause a crash in cases where the
> > vport failed to initialize. Following trace is from an instance where
> > the driver failed during an attempt to create a VF:
> > [ 1661.543624] idpf 0000:84:00.7: Device HW Reset initiated [
> > 1722.923726] idpf 0000:84:00.7: Transaction timed-out (op:1
> > cookie:2900 vc_op:1 salt:29 timeout:60000ms) [ 1723.353263] BUG:
> > kernel NULL pointer dereference, address: 0000000000000028 ...
> > [ 1723.358472] RIP: 0010:idpf_remove+0x11c/0x200 [idpf] ...
> > [ 1723.364973] Call Trace:
> > [ 1723.365475] <TASK>
> > [ 1723.365972] pci_device_remove+0x42/0xb0 [ 1723.366481]
> > device_release_driver_internal+0x1a9/0x210
> > [ 1723.366987] pci_stop_bus_device+0x6d/0x90 [ 1723.367488]
> > pci_stop_and_remove_bus_device+0x12/0x20
> > [ 1723.367971] pci_iov_remove_virtfn+0xbd/0x120 [ 1723.368309]
> > sriov_disable+0x34/0xe0 [ 1723.368643]
> > idpf_sriov_configure+0x58/0x140 [idpf] [ 1723.368982]
> > sriov_numvfs_store+0xda/0x1c0
> >
> > Avoid the NULL pointer dereference by adding NULL pointer check for
> > vport_config[i], before freeing user_config.q_coalesce.
> >
> > Fixes: e1e3fec3e34b ("idpf: preserve coalescing settings across
> > resets")
> > Signed-off-by: Emil Tantilov <[email protected]>
> > Reviewed-by: Chittim Madhu <[email protected]>
>
> Thanks,
>
> I agree that prior to the cited commit adapter->vport_config[i] being NULL was
> harmless. But afterwards a NULL pointer dereference would occur.
>
> It also seems to me that the possibility of adapter->vport_config[i] being
> null,
> via an error in idpf_vport_alloc() has existed since vport configuration was
> added by commit 0fe45467a104 ("idpf: add create vport and netdev
> configuration"). (Which predates the cited commit.)
>
> Reviewed-by: Simon Horman <[email protected]>
Tested-by: Samuel Salin <[email protected]>
