[PATCH net v2] ice: clear number of qs when rings are free

[Michal Swiatkowski <michal.swiatkowski@linux.intel.com>]

In case rebuild fails not clearing this field can lead to call trace.

[  +0.009792] BUG: kernel NULL pointer dereference, address: 0000000000000000
[  +0.000009] #PF: supervisor read access in kernel mode
[  +0.000006] #PF: error_code(0x0000) - not-present page
[  +0.000005] PGD 0 P4D 0
[  +0.000009] Oops: 0000 [#1] PREEMPT SMP PTI
[  +0.000009] CPU: 45 PID: 77867 Comm: ice-ptp-0000:60 Kdump: loaded Tainted: G S         OE      6.2.0-rc6+ #110
[  +0.000010] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.11.2 004/21/2021
[  +0.000005] RIP: 0010:ice_ptp_update_cached_phctime+0xb0/0x130 [ice]
[  +0.000145] Code: fa 7e 55 48 8b 93 48 01 00 00 48 8b 0c fa 48 85 c9 74 e1 8b 51 68 85 d2 75 da 66 83 b9 86 04 00 00 00 74 d0 31 d2 48 8b 71 20 <48> 8b 34 d6 48 85 f6 74 07 48 89 86 d8 00 00 00 0f b7 b1 86 04 00
[  +0.000008] RSP: 0018:ffffa036cf7c7ea8 EFLAGS: 00010246
[  +0.000008] RAX: 174ab1a8ab400f43 RBX: ffff937cda2c01a0 RCX: ffff937cdca9b028
[  +0.000005] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
[  +0.000005] RBP: ffffa036cf7c7eb8 R08: 0000000000000000 R09: 0000000000000000
[  +0.000005] R10: 0000000000000080 R11: 0000000000000001 R12: ffff937cdc971f40
[  +0.000006] R13: ffff937cdc971f44 R14: 0000000000000001 R15: ffffffffc13f3210
[  +0.000005] FS:  0000000000000000(0000) GS:ffff93826f980000(0000) knlGS:0000000000000000
[  +0.000006] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  +0.000006] CR2: 0000000000000000 CR3: 00000004b7310002 CR4: 00000000007726e0
[  +0.000006] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  +0.000004] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  +0.000005] PKRU: 55555554
[  +0.000004] Call Trace:
[  +0.000004]  <TASK>
[  +0.000007]  ice_ptp_periodic_work+0x2a/0x60 [ice]
[  +0.000126]  kthread_worker_fn+0xa6/0x250
[  +0.000014]  ? __pfx_kthread_worker_fn+0x10/0x10
[  +0.000010]  kthread+0xfc/0x130
[  +0.000009]  ? __pfx_kthread+0x10/0x10
[  +0.000010]  ret_from_fork+0x29/0x50

ice_ptp_update_cached_phctime() is calling ice_for_each_rxq macro, in
case of rebuild fail the rx_ring is NULL and there is NULL pointer
dereference.

Also for future safety it is better to clear the size values for tx and
rx ring when they are cleared.

Fixes: 6624e780a577 ("ice: split ice_vsi_setup into smaller functions")
Reported-by: Mateusz Palczewski <mateusz.palczewski@intel.com>
Signed-off-by: Michal Swiatkowski <michal.swiatkowski@linux.intel.com>
---
v1 --> v2:
 * change subject to net and add fixes tag
---
 drivers/net/ethernet/intel/ice/ice_lib.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/intel/ice/ice_lib.c b/drivers/net/ethernet/intel/ice/ice_lib.c
index 0f52ea38b6f3..b8317001ad34 100644
--- a/drivers/net/ethernet/intel/ice/ice_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_lib.c
@@ -330,10 +330,12 @@ static void ice_vsi_free_arrays(struct ice_vsi *vsi)
 		vsi->q_vectors = NULL;
 	}
 	if (vsi->tx_rings) {
+		vsi->num_txq = 0;
 		devm_kfree(dev, vsi->tx_rings);
 		vsi->tx_rings = NULL;
 	}
 	if (vsi->rx_rings) {
+		vsi->num_rxq = 0;
 		devm_kfree(dev, vsi->rx_rings);
 		vsi->rx_rings = NULL;
 	}
-- 
2.36.1