From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 33BF939EF27; Thu, 2 Jul 2026 16:33:00 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783009981; cv=none; b=KqJ7rh4Ay3Lq7X33Vw7avUyj1WYdYvMOto8f+mEqOC6PW0xtBNN+15z7dgOpsYSXouvpo46Zc5iSCCslTxYSNcE44ZaqsK2M3UTn2LA4SijI6cWrS527fDAxtm/K3t20k2DQ5N0Y6yxIQiXTM9u1MDEm1IuEqeE0eY2dKnP69ho= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783009981; c=relaxed/simple; bh=nm0TBhVHDahzcsjqy7y/gIMi/xSZXBjYxsqzPsJoNtk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Lwx4xnrkq+2x1G+quONfIocrVWP4uENOC9JP3yZ/z3o7z/JjM6j2GAldJzXjnn9cZGLOW+anzxtAjatyDCzecNcS0TtS3ja2DEcQzcr6j5A0lZ/DFeFfuYRAbWQzgfG0jsS568FhGSRuHIfJz1gwS9/rMAFgJ2lg/zjF9Si9/nU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=LzO+Pub8; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="LzO+Pub8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 995AC1F000E9; Thu, 2 Jul 2026 16:32:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1783009980; bh=UMHWwbWzbgicf2k1eeG0qO7mQNuk/siS5wI10Zh0ZXY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LzO+Pub8hTZ5RND42r/GPJi0AqEYJi+oVTLjS9DA/PGQRCgo1ofpOdKa5dFZVAo1K zojoshHWtOvHO+K/uSQ4jVK+LNBXulLAp2BluxMQRgxuPwjp05LL0C0yaLSenKcGSY c3WBg7NFhH0oE+ysms12uM+TEri/GyzJJrs1Nx/E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, Sven Eckelmann , Sasha Levin Subject: [PATCH 6.1 058/129] batman-adv: bla: annotate lasttime access with READ/WRITE_ONCE Date: Thu, 2 Jul 2026 18:19:37 +0200 Message-ID: <20260702155113.347050304@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260702155112.163984240@linuxfoundation.org> References: <20260702155112.163984240@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit 98b0fb191c878a64cbaebfe231d96d57576acf8c upstream. The lasttime field for claim, backbone_gw, and loopdetect tracks the jiffies value of the most recent activity and is used to detect timeouts. These accesses are not consistently protected by a lock, so READ_ONCE/WRITE_ONCE must be used to prevent data races caused by compiler optimizations. Cc: stable@kernel.org Fixes: 23721387c409 ("batman-adv: add basic bridge loop avoidance code") Signed-off-by: Sven Eckelmann Signed-off-by: Sasha Levin --- net/batman-adv/bridge_loop_avoidance.c | 28 +++++++++++++------------- 1 file changed, 14 insertions(+), 14 deletions(-) diff --git a/net/batman-adv/bridge_loop_avoidance.c b/net/batman-adv/bridge_loop_avoidance.c index cfb1eb25c6ac4d..ac12c06f11b89e 100644 --- a/net/batman-adv/bridge_loop_avoidance.c +++ b/net/batman-adv/bridge_loop_avoidance.c @@ -512,7 +512,7 @@ batadv_bla_get_backbone_gw(struct batadv_priv *bat_priv, const u8 *orig, return NULL; entry->vid = vid; - entry->lasttime = jiffies; + WRITE_ONCE(entry->lasttime, jiffies); entry->crc = BATADV_BLA_CRC_INIT; entry->bat_priv = bat_priv; spin_lock_init(&entry->crc_lock); @@ -580,7 +580,7 @@ batadv_bla_update_own_backbone_gw(struct batadv_priv *bat_priv, if (unlikely(!backbone_gw)) return; - backbone_gw->lasttime = jiffies; + WRITE_ONCE(backbone_gw->lasttime, jiffies); batadv_backbone_gw_put(backbone_gw); } @@ -714,7 +714,7 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, ether_addr_copy(claim->addr, mac); spin_lock_init(&claim->backbone_lock); claim->vid = vid; - claim->lasttime = jiffies; + WRITE_ONCE(claim->lasttime, jiffies); kref_get(&backbone_gw->refcount); claim->backbone_gw = backbone_gw; kref_init(&claim->refcount); @@ -736,7 +736,7 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, return; } } else { - claim->lasttime = jiffies; + WRITE_ONCE(claim->lasttime, jiffies); if (claim->backbone_gw == backbone_gw) /* no need to register a new backbone */ goto claim_free_ref; @@ -769,7 +769,7 @@ static void batadv_bla_add_claim(struct batadv_priv *bat_priv, spin_lock_bh(&backbone_gw->crc_lock); backbone_gw->crc ^= crc16(0, claim->addr, ETH_ALEN); spin_unlock_bh(&backbone_gw->crc_lock); - backbone_gw->lasttime = jiffies; + WRITE_ONCE(backbone_gw->lasttime, jiffies); claim_free_ref: batadv_claim_put(claim); @@ -858,7 +858,7 @@ static bool batadv_handle_announce(struct batadv_priv *bat_priv, u8 *an_addr, return true; /* handle as ANNOUNCE frame */ - backbone_gw->lasttime = jiffies; + WRITE_ONCE(backbone_gw->lasttime, jiffies); crc = ntohs(*((__force __be16 *)(&an_addr[4]))); batadv_dbg(BATADV_DBG_BLA, bat_priv, @@ -1253,7 +1253,7 @@ static void batadv_bla_purge_backbone_gw(struct batadv_priv *bat_priv, int now) head, hash_entry) { if (now) goto purge_now; - if (!batadv_has_timed_out(backbone_gw->lasttime, + if (!batadv_has_timed_out(READ_ONCE(backbone_gw->lasttime), BATADV_BLA_BACKBONE_TIMEOUT)) continue; @@ -1334,7 +1334,7 @@ static void batadv_bla_purge_claims(struct batadv_priv *bat_priv, primary_if->net_dev->dev_addr)) goto skip; - if (!batadv_has_timed_out(claim->lasttime, + if (!batadv_has_timed_out(READ_ONCE(claim->lasttime), BATADV_BLA_CLAIM_TIMEOUT)) goto skip; @@ -1494,7 +1494,7 @@ static void batadv_bla_periodic_work(struct work_struct *work) eth_random_addr(bat_priv->bla.loopdetect_addr); bat_priv->bla.loopdetect_addr[0] = 0xba; bat_priv->bla.loopdetect_addr[1] = 0xbe; - bat_priv->bla.loopdetect_lasttime = jiffies; + WRITE_ONCE(bat_priv->bla.loopdetect_lasttime, jiffies); atomic_set(&bat_priv->bla.loopdetect_next, BATADV_BLA_LOOPDETECT_PERIODS); @@ -1515,7 +1515,7 @@ static void batadv_bla_periodic_work(struct work_struct *work) primary_if->net_dev->dev_addr)) continue; - backbone_gw->lasttime = jiffies; + WRITE_ONCE(backbone_gw->lasttime, jiffies); batadv_bla_send_announce(bat_priv, backbone_gw); if (send_loopdetect) @@ -1900,7 +1900,7 @@ batadv_bla_loopdetect_check(struct batadv_priv *bat_priv, struct sk_buff *skb, /* If the packet came too late, don't forward it on the mesh * but don't consider that as loop. It might be a coincidence. */ - if (batadv_has_timed_out(bat_priv->bla.loopdetect_lasttime, + if (batadv_has_timed_out(READ_ONCE(bat_priv->bla.loopdetect_lasttime), BATADV_BLA_LOOPDETECT_TIMEOUT)) return true; @@ -2016,7 +2016,7 @@ bool batadv_bla_rx(struct batadv_priv *bat_priv, struct sk_buff *skb, if (own_claim) { /* ... allow it in any case */ - claim->lasttime = jiffies; + WRITE_ONCE(claim->lasttime, jiffies); goto allow; } @@ -2118,7 +2118,7 @@ bool batadv_bla_tx(struct batadv_priv *bat_priv, struct sk_buff *skb, /* if yes, the client has roamed and we have * to unclaim it. */ - if (batadv_has_timed_out(claim->lasttime, 100)) { + if (batadv_has_timed_out(READ_ONCE(claim->lasttime), 100)) { /* only unclaim if the last claim entry is * older than 100 ms to make sure we really * have a roaming client here. @@ -2372,7 +2372,7 @@ batadv_bla_backbone_dump_entry(struct sk_buff *msg, u32 portid, backbone_crc = backbone_gw->crc; spin_unlock_bh(&backbone_gw->crc_lock); - msecs = jiffies_to_msecs(jiffies - backbone_gw->lasttime); + msecs = jiffies_to_msecs(jiffies - READ_ONCE(backbone_gw->lasttime)); if (is_own) if (nla_put_flag(msg, BATADV_ATTR_BLA_OWN)) { -- 2.53.0