Subject: [net 07/12] net/mlx5e: Verify dev is present in get devlink port ndo

From: Saeed Mahameed <[email-masked]>
Date: Wed, 9 Jun 2021 17:21:50 -0700

From: Chris Mi <[email-masked]>

When changing eswitch mode, the netdev is detached from the
hardware resources. So verify dev is present in get devlink
port ndo. Otherwise, we will hit the following panic:

[241535.973539] RIP: 0010:__devlink_port_phys_port_name_get+0x13/0x1b0
[241535.976471] RSP: 0018:ffff9eaf0ae1b7c8 EFLAGS: 00010292
[241535.977471] RAX: 000000000002d370 RBX: 000000000002d370 RCX: 0000000000000000
[241535.978479] RDX: 0000000000000010 RSI: ffff9eaf0ae1b858 RDI: 000000000002d370
[241535.979482] RBP: ffff9eaf0ae1b7e0 R08: 000000000000002a R09: ffff8888d54d13da
[241535.980486] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8888e6700000
[241535.981491] R13: ffff9eaf0ae1b858 R14: 0000000000000010 R15: 0000000000000000
[241535.982489] FS:  00007fd374ef3740(0000) GS:ffff88909ea00000(0000) knlGS:0000000000000000
[241535.983494] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[241535.984487] CR2: 000000000002d444 CR3: 000000089fd26006 CR4: 00000000003706e0
[241535.985502] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[241535.986499] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[241535.987477] Call Trace:
[241535.988426]  ? nla_put_64bit+0x71/0xa0
[241535.989368]  devlink_compat_phys_port_name_get+0x50/0xa0
[241535.990312]  dev_get_phys_port_name+0x4b/0x60
[241535.991252]  rtnl_fill_ifinfo+0x57b/0xcb0
[241535.992192]  rtnl_dump_ifinfo+0x58f/0x6d0
[241535.993123]  ? ksize+0x14/0x20
[241535.994033]  ? __alloc_skb+0xe8/0x250
[241535.994935]  netlink_dump+0x17c/0x300
[241535.995821]  netlink_recvmsg+0x1de/0x2c0
[241535.996677]  sock_recvmsg+0x70/0x80
[241535.997518]  ____sys_recvmsg+0x9b/0x1b0
[241535.998360]  ? iovec_from_user+0x82/0x120
[241535.999202]  ? __import_iovec+0x2c/0x130
[241536.000031]  ___sys_recvmsg+0x94/0x130
[241536.000850]  ? __handle_mm_fault+0x56d/0x6e0
[241536.001668]  __sys_recvmsg+0x5f/0xb0
[241536.002464]  ? syscall_enter_from_user_mode+0x2b/0x80
[241536.003242]  __x64_sys_recvmsg+0x1f/0x30
[241536.004008]  do_syscall_64+0x38/0x50
[241536.004767]  entry_SYSCALL_64_after_hwframe+0x44/0xae
[241536.005532] RIP: 0033:0x7fd375014f47

Fixes: 2ff349c5edfe ("net/mlx5e: Verify dev is present in some ndos")
Signed-off-by: Roi Dayan <[email-masked]>
Signed-off-by: Chris Mi <[email-masked]>
Signed-off-by: Saeed Mahameed <[email-masked]>
---
 drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c b/drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c
index 0dd7615e5931..bc33eaada3b9 100644
--- a/drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/en/devlink.c
@@ -64,6 +64,8 @@ struct devlink_port *mlx5e_get_devlink_port(struct net_device *dev)
 	struct mlx5e_priv *priv = netdev_priv(dev);
 	struct devlink_port *port;
 
+	if (!netif_device_present(dev))
+		return NULL;
 	port = mlx5e_devlink_get_dl_port(priv);
 	if (port->registered)
 		return port;
-- 
2.31.1