[PATCH net 02/13] idpf: skip deallocating bufq_sets from rx_qgrp if it is NULL

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

From: Li Li <boolli@google.com>

In idpf_rxq_group_alloc(), if rx_qgrp->splitq.bufq_sets failed to get
allocated:

	rx_qgrp->splitq.bufq_sets = kcalloc(vport->num_bufqs_per_qgrp,
					    sizeof(struct idpf_bufq_set),
					    GFP_KERNEL);
	if (!rx_qgrp->splitq.bufq_sets) {
		err = -ENOMEM;
		goto err_alloc;
	}

idpf_rxq_group_rel() would attempt to deallocate it in
idpf_rxq_sw_queue_rel(), causing a kernel panic:

```
[    7.967242] early-network-sshd-n-rexd[3148]: knetbase: Info: [    8.127804] BUG: kernel NULL pointer dereference, address: 00000000000000c0
...
[    8.129779] RIP: 0010:idpf_rxq_group_rel+0x101/0x170
...
[    8.133854] Call Trace:
[    8.133980]  <TASK>
[    8.134092]  idpf_vport_queues_alloc+0x286/0x500
[    8.134313]  idpf_vport_open+0x4d/0x3f0
[    8.134498]  idpf_open+0x71/0xb0
[    8.134668]  __dev_open+0x142/0x260
[    8.134840]  netif_open+0x2f/0xe0
[    8.135004]  dev_open+0x3d/0x70
[    8.135166]  bond_enslave+0x5ed/0xf50
[    8.135345]  ? nla_put_ifalias+0x3d/0x90
[    8.135533]  ? kvfree_call_rcu+0xb5/0x3b0
[    8.135725]  ? kvfree_call_rcu+0xb5/0x3b0
[    8.135916]  do_set_master+0x114/0x160
[    8.136098]  do_setlink+0x412/0xfb0
[    8.136269]  ? security_sock_rcv_skb+0x2a/0x50
[    8.136509]  ? sk_filter_trim_cap+0x7c/0x320
[    8.136714]  ? skb_queue_tail+0x20/0x50
[    8.136899]  ? __nla_validate_parse+0x92/0xe50
[    8.137112]  ? security_capable+0x35/0x60
[    8.137304]  rtnl_newlink+0x95c/0xa00
[    8.137483]  ? __rtnl_unlock+0x37/0x70
[    8.137664]  ? netdev_run_todo+0x63/0x530
[    8.137855]  ? allocate_slab+0x280/0x870
[    8.138044]  ? security_capable+0x35/0x60
[    8.138235]  rtnetlink_rcv_msg+0x2e6/0x340
[    8.138431]  ? __pfx_rtnetlink_rcv_msg+0x10/0x10
[    8.138650]  netlink_rcv_skb+0x16a/0x1a0
[    8.138840]  netlink_unicast+0x20a/0x320
[    8.139028]  netlink_sendmsg+0x304/0x3b0
[    8.139217]  __sock_sendmsg+0x89/0xb0
[    8.139399]  ____sys_sendmsg+0x167/0x1c0
[    8.139588]  ? ____sys_recvmsg+0xed/0x150
[    8.139780]  ___sys_sendmsg+0xdd/0x120
[    8.139960]  ? ___sys_recvmsg+0x124/0x1e0
[    8.140152]  ? rcutree_enqueue+0x1f/0xb0
[    8.140341]  ? rcutree_enqueue+0x1f/0xb0
[    8.140528]  ? call_rcu+0xde/0x2a0
[    8.140695]  ? evict+0x286/0x2d0
[    8.140856]  ? rcutree_enqueue+0x1f/0xb0
[    8.141043]  ? kmem_cache_free+0x2c/0x350
[    8.141236]  __x64_sys_sendmsg+0x72/0xc0
[    8.141424]  do_syscall_64+0x6f/0x890
[    8.141603]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[    8.141841] RIP: 0033:0x7f2799d21bd0
...
[    8.149905] Kernel panic - not syncing: Fatal exception
[    8.175940] Kernel Offset: 0xf800000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff)
[    8.176425] Rebooting in 10 seconds..
```

Tested: With this patch, the kernel panic no longer appears.

Fixes: 95af467d9a4e ("idpf: configure resources for RX queues")
Signed-off-by: Li Li <boolli@google.com>
Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Tested-by: Samuel Salin <Samuel.salin@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/idpf/idpf_txrx.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/ethernet/intel/idpf/idpf_txrx.c b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
index 761a77510467..59aafadae3d0 100644
--- a/drivers/net/ethernet/intel/idpf/idpf_txrx.c
+++ b/drivers/net/ethernet/intel/idpf/idpf_txrx.c
@@ -1341,6 +1341,9 @@ static void idpf_txq_group_rel(struct idpf_q_vec_rsrc *rsrc)
  */
 static void idpf_rxq_sw_queue_rel(struct idpf_rxq_group *rx_qgrp)
 {
+	if (!rx_qgrp->splitq.bufq_sets)
+		return;
+
 	for (unsigned int i = 0; i < rx_qgrp->splitq.num_bufq_sets; i++) {
 		struct idpf_bufq_set *bufq_set = &rx_qgrp->splitq.bufq_sets[i];
 
-- 
2.47.1