IB/IPoIB: Fix legacy IPoIB due to wrong number of queues

[ Upstream commit e632291 ]

The cited commit creates child PKEY interfaces over netlink will
multiple tx and rx queues, but some devices doesn't support more than 1
tx and 1 rx queues. This causes to a crash when traffic is sent over the
PKEY interface due to the parent having a single queue but the child
having multiple queues.

This patch fixes the number of queues to 1 for legacy IPoIB at the
earliest possible point in time.

BUG: kernel NULL pointer dereference, address: 000000000000036b
PGD 0 P4D 0
Oops: 0000 [#1] SMP
CPU: 4 PID: 209665 Comm: python3 Not tainted 6.1.0_for_upstream_min_debug_2022_12_12_17_02 #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
RIP: 0010:kmem_cache_alloc+0xcb/0x450
Code: ce 7e 49 8b 50 08 49 83 78 10 00 4d 8b 28 0f 84 cb 02 00 00 4d 85 ed 0f 84 c2 02 00 00 41 8b 44 24 28 48 8d 4a
01 49 8b 3c 24 <49> 8b 5c 05 00 4c 89 e8 65 48 0f c7 0f 0f 94 c0 84 c0 74 b8 41 8b
RSP: 0018:ffff88822acbbab8 EFLAGS: 00010202
RAX: 0000000000000070 RBX: ffff8881c28e3e00 RCX: 00000000064f8dae
RDX: 00000000064f8dad RSI: 0000000000000a20 RDI: 0000000000030d00
RBP: 0000000000000a20 R08: ffff8882f5d30d00 R09: ffff888104032f40
R10: ffff88810fade828 R11: 736f6d6570736575 R12: ffff88810081c000
R13: 00000000000002fb R14: ffffffff817fc865 R15: 0000000000000000
FS:  00007f9324ff9700(0000) GS:ffff8882f5d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000000036b CR3: 00000001125af004 CR4: 0000000000370ea0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 skb_clone+0x55/0xd0
 ip6_finish_output2+0x3fe/0x690
 ip6_finish_output+0xfa/0x310
 ip6_send_skb+0x1e/0x60
 udp_v6_send_skb+0x1e5/0x420
 udpv6_sendmsg+0xb3c/0xe60
 ? ip_mc_finish_output+0x180/0x180
 ? __switch_to_asm+0x3a/0x60
 ? __switch_to_asm+0x34/0x60
 sock_sendmsg+0x33/0x40
 __sys_sendto+0x103/0x160
 ? _copy_to_user+0x21/0x30
 ? kvm_clock_get_cycles+0xd/0x10
 ? ktime_get_ts64+0x49/0xe0
 __x64_sys_sendto+0x25/0x30
 do_syscall_64+0x3d/0x90
 entry_SYSCALL_64_after_hwframe+0x46/0xb0
RIP: 0033:0x7f9374f1ed14
Code: 42 41 f8 ff 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b
7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 68 41 f8 ff 48 8b
RSP: 002b:00007f9324ff7bd0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f9324ff7cc8 RCX: 00007f9374f1ed14
RDX: 00000000000002fb RSI: 00007f93000052f0 RDI: 0000000000000030
RBP: 0000000000000000 R08: 00007f9324ff7d40 R09: 000000000000001c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 000000012a05f200 R14: 0000000000000001 R15: 00007f9374d57bdc
 </TASK>

Fixes: dbc94a0 ("IB/IPoIB: Fix queue count inconsistency for PKEY child interfaces")
Signed-off-by: Dragos Tatulea <dtatulea@nvidia.com>
Link: https://lore.kernel.org/r/95eb6b74c7cf49fa46281f9d056d685c9fa11d38.1674584576.git.leon@kernel.org
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/infiniband/ulp/ipoib/ipoib_main.c

@@ -2200,6 +2200,14 @@ int ipoib_intf_init(struct ib_device *hca, u32 port, const char *name,
 		rn->attach_mcast = ipoib_mcast_attach;
 		rn->detach_mcast = ipoib_mcast_detach;
 		rn->hca = hca;
+
+		rc = netif_set_real_num_tx_queues(dev, 1);
+		if (rc)
+			goto out;
+
+		rc = netif_set_real_num_rx_queues(dev, 1);
+		if (rc)
+			goto out;
 	}
 
 	priv->rn_ops = dev->netdev_ops;