blob: 05e368cd2ede96b9a77579e5d4e844fcf80ee1b0 [file] [log] [blame]
From: Felix Fietkau <nbd@nbd.name>
Date: Wed, 15 Feb 2023 15:21:37 +0100
Subject: [PATCH] wifi: mac80211: fix race in mesh sequence number
assignment
Since the sequence number is shared across different tx queues, it needs
to be atomic in order to avoid accidental duplicate assignment
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -695,7 +695,7 @@ struct ieee80211_if_mesh {
struct mesh_stats mshstats;
struct mesh_config mshcfg;
atomic_t estab_plinks;
- u32 mesh_seqnum;
+ atomic_t mesh_seqnum;
bool accepting_plinks;
int num_gates;
struct beacon_data __rcu *beacon;
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -752,10 +752,8 @@ unsigned int ieee80211_new_mesh_header(s
meshhdr->ttl = sdata->u.mesh.mshcfg.dot11MeshTTL;
- /* FIXME: racy -- TX on multiple queues can be concurrent */
- put_unaligned(cpu_to_le32(sdata->u.mesh.mesh_seqnum), &meshhdr->seqnum);
- sdata->u.mesh.mesh_seqnum++;
-
+ put_unaligned_le32(atomic_inc_return(&sdata->u.mesh.mesh_seqnum),
+ &meshhdr->seqnum);
if (addr4or5 && !addr6) {
meshhdr->flags |= MESH_FLAGS_AE_A4;
memcpy(meshhdr->eaddr1, addr4or5, ETH_ALEN);