[PATCH net 3/4] ice: Fix NULL pointer dereference in ice_vsi_set_napi_queues

[Tony Nguyen <anthony.l.nguyen@intel.com>]

From: Aaron Ma <aaron.ma@canonical.com>

Add NULL pointer checks in ice_vsi_set_napi_queues() to prevent crashes
during resume from suspend when rings[q_idx]->q_vector is NULL.

Tested adaptor:
60:00.0 Ethernet controller [0200]: Intel Corporation Ethernet Controller E810-XXV for SFP [8086:159b] (rev 02)
        Subsystem: Intel Corporation Ethernet Network Adapter E810-XXV-2 [8086:4003]

SR-IOV state: both disabled and enabled can reproduce this issue.

kernel version: v6.18

Reproduce steps:
Boot up and execute suspend like systemctl suspend or rtcwake.

Log:
<1>[  231.443607] BUG: kernel NULL pointer dereference, address: 0000000000000040
<1>[  231.444052] #PF: supervisor read access in kernel mode
<1>[  231.444484] #PF: error_code(0x0000) - not-present page
<6>[  231.444913] PGD 0 P4D 0
<4>[  231.445342] Oops: Oops: 0000 [#1] SMP NOPTI
<4>[  231.446635] RIP: 0010:netif_queue_set_napi+0xa/0x170
<4>[  231.447067] Code: 31 f6 31 ff c3 cc cc cc cc 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 44 00 00 48 85 c9 74 0b <48> 83 79 30 00 0f 84 39 01 00 00 55 41 89 d1 49 89 f8 89 f2 48 89
<4>[  231.447513] RSP: 0018:ffffcc780fc078c0 EFLAGS: 00010202
<4>[  231.447961] RAX: ffff8b848ca30400 RBX: ffff8b848caf2028 RCX: 0000000000000010
<4>[  231.448443] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8b848dbd4000
<4>[  231.448896] RBP: ffffcc780fc078e8 R08: 0000000000000000 R09: 0000000000000000
<4>[  231.449345] R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001
<4>[  231.449817] R13: ffff8b848dbd4000 R14: ffff8b84833390c8 R15: 0000000000000000
<4>[  231.450265] FS:  00007c7b29e9d740(0000) GS:ffff8b8c068e2000(0000) knlGS:0000000000000000
<4>[  231.450715] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
<4>[  231.451179] CR2: 0000000000000040 CR3: 000000030626f004 CR4: 0000000000f72ef0
<4>[  231.451629] PKRU: 55555554
<4>[  231.452076] Call Trace:
<4>[  231.452549]  <TASK>
<4>[  231.452996]  ? ice_vsi_set_napi_queues+0x4d/0x110 [ice]
<4>[  231.453482]  ice_resume+0xfd/0x220 [ice]
<4>[  231.453977]  ? __pfx_pci_pm_resume+0x10/0x10
<4>[  231.454425]  pci_pm_resume+0x8c/0x140
<4>[  231.454872]  ? __pfx_pci_pm_resume+0x10/0x10
<4>[  231.455347]  dpm_run_callback+0x5f/0x160
<4>[  231.455796]  ? dpm_wait_for_superior+0x107/0x170
<4>[  231.456244]  device_resume+0x177/0x270
<4>[  231.456708]  dpm_resume+0x209/0x2f0
<4>[  231.457151]  dpm_resume_end+0x15/0x30
<4>[  231.457596]  suspend_devices_and_enter+0x1da/0x2b0
<4>[  231.458054]  enter_state+0x10e/0x570

Add defensive checks for both the ring pointer and its q_vector
before dereferencing, allowing the system to resume successfully even when
q_vectors are unmapped.

Fixes: 2a5dc090b92cf ("ice: move netif_queue_set_napi to rtnl-protected sections")
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Aaron Ma <aaron.ma@canonical.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/ice/ice_lib.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 98010354db15..d47af94f31a9 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -2783,12 +2783,14 @@ void ice_vsi_set_napi_queues(struct ice_vsi *vsi)
 
 	ASSERT_RTNL();
 	ice_for_each_rxq(vsi, q_idx)
-		netif_queue_set_napi(netdev, q_idx, NETDEV_QUEUE_TYPE_RX,
-				     &vsi->rx_rings[q_idx]->q_vector->napi);
+		if (vsi->rx_rings[q_idx] && vsi->rx_rings[q_idx]->q_vector)
+			netif_queue_set_napi(netdev, q_idx, NETDEV_QUEUE_TYPE_RX,
+					     &vsi->rx_rings[q_idx]->q_vector->napi);
 
 	ice_for_each_txq(vsi, q_idx)
-		netif_queue_set_napi(netdev, q_idx, NETDEV_QUEUE_TYPE_TX,
-				     &vsi->tx_rings[q_idx]->q_vector->napi);
+		if (vsi->tx_rings[q_idx] && vsi->tx_rings[q_idx]->q_vector)
+			netif_queue_set_napi(netdev, q_idx, NETDEV_QUEUE_TYPE_TX,
+					     &vsi->tx_rings[q_idx]->q_vector->napi);
 	/* Also set the interrupt number for the NAPI */
 	ice_for_each_q_vector(vsi, v_idx) {
 		struct ice_q_vector *q_vector = vsi->q_vectors[v_idx];
-- 
2.47.1