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 DD9823403F9; Sat, 30 May 2026 17:31:38 +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=1780162299; cv=none; b=MLzX84EV2/ShM4X6odkWlm6M7uqVRv32EpHSATO590n9yITDZIwoaCc6J1xv576yZFvz/tI25MSV6qShV1Ob1mDQWobmcTsaP+OS9YwU4bmpaYsEwz9Rrnj4JX684HF60N6w6FMVn2EnyyAkVnfj2tOLSZm1Q3ywMuoBHoyWR7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780162299; c=relaxed/simple; bh=u68KilQYUnyf2HH8P70VHdHzN+dbvY9kHKz/mHeiTus=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=dzvsTpd7HMY9tRQH+5HyPg1JdUuwQHcQaFQjqzHmGyppOtbqxYd/6LntqaXubafWG/z5nIC6rgpI4PltixHZM5j6aFvalCM6iMl7NGcEbf4ErmMsvM4QkoVWsKjngTC8v81FVZ5snaBE/ZgLuyXo44oyAVqmKuCJmRsxYvh0TVA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=eYLcZJ/7; 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="eYLcZJ/7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2F4F1F00893; Sat, 30 May 2026 17:31:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780162298; bh=FD5q1Mai6UgvL8WwvJv4I5X4JpdT3oMGeS40F1PWsow=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=eYLcZJ/7Lr1+ojuoEzSDm/yLc4LRU5Qt8rT7CalhDtnlXeY1xfWTvPHCVb7NGWU7y u75y7Tl0Sa4kFbKhwEMCwRcxnKZ+L+76vY3w4i7Od7GJDtoFWqn2SGz7K5d5Gbx8WK J6S5Dg2z0iEYKdMWremV40/LHnnpjNcHj9YG+DQo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, stable@kernel.org, =?UTF-8?q?Linus=20L=C3=BCssing?= , Sven Eckelmann Subject: [PATCH 6.1 880/969] batman-adv: mcast: fix use-after-free in orig_node RCU release Date: Sat, 30 May 2026 18:06:44 +0200 Message-ID: <20260530160324.988719350@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260530160300.485627683@linuxfoundation.org> References: <20260530160300.485627683@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-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit 20c2d6a20ca936f5aaa6dd40f73f262ac45c87cc upstream. batadv_mcast_purge_orig() removes entries from RCU-protected hlists but does not wait for an RCU grace period before returning. Concurrent RCU readers may still accesses references to those entries at the point of removal. RCU-protected readers trying to operate on entries like orig->mcast_want_all_ipv6_node will then access already freed memory. Fix this by moving batadv_mcast_purge_orig() to batadv_orig_node_release(), just before the call_rcu() invocation. This ensures RCU readers that were active at purge time have drained before the orig_node memory is reclaimed. Cc: stable@kernel.org Fixes: ab49886e3da7 ("batman-adv: Add IPv4 link-local/IPv6-ll-all-nodes multicast support") Acked-by: Linus Lüssing Signed-off-by: Sven Eckelmann Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/originator.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/net/batman-adv/originator.c +++ b/net/batman-adv/originator.c @@ -823,8 +823,6 @@ static void batadv_orig_node_free_rcu(st orig_node = container_of(rcu, struct batadv_orig_node, rcu); - batadv_mcast_purge_orig(orig_node); - batadv_frag_purge_orig(orig_node, NULL); kfree(orig_node->tt_buff); @@ -878,6 +876,8 @@ void batadv_orig_node_release(struct kre /* Free nc_nodes */ batadv_nc_purge_orig(orig_node->bat_priv, orig_node, NULL); + batadv_mcast_purge_orig(orig_node); + call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu); }