Commit efcce449 authored Oct 09, 2024 by Benjamin Poirier Committed by Zhang Changzhong Oct 09, 2024

net/mlx5: Fix bridge mode operations when there are no VFs

mainline inclusion
from mainline-v6.11
commit b1d305abef4640af1b4f1b4774d513cd81b10cfc
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IAU9OW
CVE: CVE-2024-46857

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=b1d305abef4640af1b4f1b4774d513cd81b10cfc



--------------------------------

Currently, trying to set the bridge mode attribute when numvfs=0 leads to a
crash:

bridge link set dev eth2 hwmode vepa

[  168.967392] BUG: kernel NULL pointer dereference, address: 0000000000000030
[...]
[  168.969989] RIP: 0010:mlx5_add_flow_rules+0x1f/0x300 [mlx5_core]
[...]
[  168.976037] Call Trace:
[  168.976188]  <TASK>
[  168.978620]  _mlx5_eswitch_set_vepa_locked+0x113/0x230 [mlx5_core]
[  168.979074]  mlx5_eswitch_set_vepa+0x7f/0xa0 [mlx5_core]
[  168.979471]  rtnl_bridge_setlink+0xe9/0x1f0
[  168.979714]  rtnetlink_rcv_msg+0x159/0x400
[  168.980451]  netlink_rcv_skb+0x54/0x100
[  168.980675]  netlink_unicast+0x241/0x360
[  168.980918]  netlink_sendmsg+0x1f6/0x430
[  168.981162]  ____sys_sendmsg+0x3bb/0x3f0
[  168.982155]  ___sys_sendmsg+0x88/0xd0
[  168.985036]  __sys_sendmsg+0x59/0xa0
[  168.985477]  do_syscall_64+0x79/0x150
[  168.987273]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  168.987773] RIP: 0033:0x7f8f7950f917

(esw->fdb_table.legacy.vepa_fdb is null)

The bridge mode is only relevant when there are multiple functions per
port. Therefore, prevent setting and getting this setting when there are no
VFs.

Note that after this change, there are no settings to change on the PF
interface using `bridge link` when there are no VFs, so the interface no
longer appears in the `bridge link` output.

Fixes: 4b89251d ("net/mlx5: Support ndo bridge_setlink and getlink")
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Reviewed-by: Cosmin Ratiu <cratiu@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>
Conflicts:
	drivers/net/ethernet/mellanox/mlx5/core/eswitch.c
[ commit b1d305abef46 ("net/mlx5: Fix bridge mode operations when there
are no VFs") not merged ]
Signed-off-by: Zhang Changzhong <zhangchangzhong@huawei.com>

parent be714bc6

drivers/net/ethernet/mellanox/mlx5/core/eswitch.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -2177,7 +2177,7 @@ int mlx5_eswitch_set_vepa(struct mlx5_eswitch *esw, u8 setting)
		return -EPERM;

		mutex_lock(&esw->state_lock);
		if (esw->mode != MLX5_ESWITCH_LEGACY) {
		if (esw->mode != MLX5_ESWITCH_LEGACY \|\| !mlx5_esw_is_fdb_created(esw)) {
		err = -EOPNOTSUPP;
		goto out;
		}
		@@ -2197,7 +2197,7 @@ int mlx5_eswitch_get_vepa(struct mlx5_eswitch esw, u8 setting)
		if (!ESW_ALLOWED(esw))
		return -EPERM;

		if (esw->mode != MLX5_ESWITCH_LEGACY)
		if (esw->mode != MLX5_ESWITCH_LEGACY \|\| !mlx5_esw_is_fdb_created(esw))
		return -EOPNOTSUPP;

		*setting = esw->fdb_table.legacy.vepa_uplink_rule ? 1 : 0;