[PATCH iwl-net] idpf: fix possible vport_config NULL pointer deref in remove

[PATCH iwl-net] idpf: fix possible vport_config NULL pointer deref in remove

[Emil Tantilov]

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 <emil.s.tantilov@intel.com>
Reviewed-by: Chittim Madhu <madhu.chittim@intel.com>
---
 drivers/net/ethernet/intel/idpf/idpf_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_main.c b/drivers/net/ethernet/intel/idpf/idpf_main.c
index 8c46481d2e1f..8cf4ff697572 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_main.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_main.c
@@ -63,6 +63,8 @@ static void idpf_remove(struct pci_dev *pdev)
 	destroy_workqueue(adapter->vc_event_wq);
 
 	for (i = 0; i < adapter->max_vports; i++) {
+		if (!adapter->vport_config[i])
+			continue;
 		kfree(adapter->vport_config[i]->user_config.q_coalesce);
 		kfree(adapter->vport_config[i]);
 		adapter->vport_config[i] = NULL;
-- 
2.37.3

Re: [PATCH iwl-net] idpf: fix possible vport_config NULL pointer deref in remove

[Simon Horman]

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 <emil.s.tantilov@intel.com>
> Reviewed-by: Chittim Madhu <madhu.chittim@intel.com>

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 <horms@kernel.org>

RE: [Intel-wired-lan] [PATCH iwl-net] idpf: fix possible vport_config NULL pointer deref in remove

[Salin, Samuel]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf Of
> Simon Horman
> Sent: Tuesday, October 14, 2025 2:25 AM
> To: Tantilov, Emil S <emil.s.tantilov@intel.com>
> Cc: intel-wired-lan@lists.osuosl.org; netdev@vger.kernel.org; Kitszel,
> Przemyslaw <przemyslaw.kitszel@intel.com>; Nguyen, Anthony L
> <anthony.l.nguyen@intel.com>; andrew+netdev@lunn.ch;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; decot@google.com; willemb@google.com; Hay, Joshua
> A <joshua.a.hay@intel.com>; Chittim, Madhu <madhu.chittim@intel.com>
> 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 <emil.s.tantilov@intel.com>
> > Reviewed-by: Chittim Madhu <madhu.chittim@intel.com>
> 
> 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 <horms@kernel.org>

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

RE: [Intel-wired-lan] [PATCH iwl-net] idpf: fix possible vport_config NULL pointer deref in remove

[Loktionov, Aleksandr]

> -----Original Message-----
> From: Intel-wired-lan <intel-wired-lan-bounces@osuosl.org> On Behalf
> Of Emil Tantilov
> Sent: Monday, October 13, 2025 5:08 PM
> To: intel-wired-lan@lists.osuosl.org
> Cc: netdev@vger.kernel.org; Kitszel, Przemyslaw
> <przemyslaw.kitszel@intel.com>; Nguyen, Anthony L
> <anthony.l.nguyen@intel.com>; andrew+netdev@lunn.ch;
> davem@davemloft.net; edumazet@google.com; kuba@kernel.org;
> pabeni@redhat.com; decot@google.com; willemb@google.com; Hay, Joshua A
> <joshua.a.hay@intel.com>; Chittim, Madhu <madhu.chittim@intel.com>;
> horms@kernel.org
> Subject: [Intel-wired-lan] [PATCH iwl-net] idpf: fix possible
> vport_config NULL pointer deref in remove
> 
> 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 <emil.s.tantilov@intel.com>
> Reviewed-by: Chittim Madhu <madhu.chittim@intel.com>
> ---
>  drivers/net/ethernet/intel/idpf/idpf_main.c | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/idpf/idpf_main.c
> b/drivers/net/ethernet/intel/idpf/idpf_main.c
> index 8c46481d2e1f..8cf4ff697572 100644
> --- a/drivers/net/ethernet/intel/idpf/idpf_main.c
> +++ b/drivers/net/ethernet/intel/idpf/idpf_main.c
> @@ -63,6 +63,8 @@ static void idpf_remove(struct pci_dev *pdev)
>  	destroy_workqueue(adapter->vc_event_wq);
> 
>  	for (i = 0; i < adapter->max_vports; i++) {
> +		if (!adapter->vport_config[i])
> +			continue;
>  		kfree(adapter->vport_config[i]->user_config.q_coalesce);
>  		kfree(adapter->vport_config[i]);
>  		adapter->vport_config[i] = NULL;
> --
> 2.37.3

Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>