Commit ecfc5638 authored by Nikolay Aleksandrov's avatar Nikolay Aleksandrov Committed by Yuan Can
Browse files

net: bridge: mst: pass vlan group directly to br_mst_vlan_set_state 

mainline inclusion
from mainline-v6.10-rc4
commit 36c92936e868601fa1f43da6758cf55805043509
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/IA6S78
CVE: CVE-2024-36979

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=36c92936e868601fa1f43da6758cf55805043509



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

Pass the already obtained vlan group pointer to br_mst_vlan_set_state()
instead of dereferencing it again. Each caller has already correctly
dereferenced it for their context. This change is required for the
following suspicious RCU dereference fix. No functional changes
intended.

Fixes: 3a7c1661ae13 ("net: bridge: mst: fix vlan use-after-free")
Reported-by: default avatar <syzbot+9bbe2de1bc9d470eb5fe@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=9bbe2de1bc9d470eb5fe


Signed-off-by: default avatarNikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/20240609103654.914987-2-razor@blackwall.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarYuan Can <yuancan@huawei.com>
parent 90b02077

net/bridge/br_mst.c

+5 −6
Original line number Diff line number Diff line
@@ -73,11 +73,10 @@ int br_mst_get_state(const struct net_device *dev, u16 msti, u8 *state) 
}

EXPORT_SYMBOL_GPL(br_mst_get_state);



static void br_mst_vlan_set_state(struct net_bridge_port *p, struct net_bridge_vlan *v,

static void br_mst_vlan_set_state(struct net_bridge_vlan_group *vg,

				  struct net_bridge_vlan *v,

				  u8 state)

{

	struct net_bridge_vlan_group *vg = nbp_vlan_group(p);



	if (br_vlan_get_state(v) == state)

		return;
@@ -121,7 +120,7 @@ int br_mst_set_state(struct net_bridge_port *p, u16 msti, u8 state, 
		if (v->brvlan->msti != msti)

			continue;



		br_mst_vlan_set_state(p, v, state);

		br_mst_vlan_set_state(vg, v, state);

	}



out:
@@ -140,13 +139,13 @@ static void br_mst_vlan_sync_state(struct net_bridge_vlan *pv, u16 msti) 
		 * it.

		 */

		if (v != pv && v->brvlan->msti == msti) {

			br_mst_vlan_set_state(pv->port, pv, v->state);

			br_mst_vlan_set_state(vg, pv, v->state);

			return;

		}

	}



	/* Otherwise, start out in a new MSTI with all ports disabled. */

	return br_mst_vlan_set_state(pv->port, pv, BR_STATE_DISABLED);

	return br_mst_vlan_set_state(vg, pv, BR_STATE_DISABLED);

}



int br_mst_vlan_set_msti(struct net_bridge_vlan *mv, u16 msti)