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 3F749282F17; Thu, 28 May 2026 20:20:47 +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=1779999648; cv=none; b=hHAutKrCsQtbak0zhnzTZJRsf/wuQyz1e/BYmFSov3B42gig++cAbThpIo4M05C6zFOIU8+Tu5H5FHP0TO+ZrSrJxt8rXD2YDMd1950PQmbLv/csufRpWBZBsUbxpoSnejHxVUc+lwDPfNUbyPkvoXENs7VSM/YSWeq2j6HUywI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779999648; c=relaxed/simple; bh=thMOqZ63rvMsjmUAJbAsQlKy1NFzLQkGn5CEKLgY/Ww=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=cLKc27Emzi0rcP8t8hK4wZl0PLXgyr+nBCgyB6Dnz8fJVkzzQyuBUazCR6Eq8qHYA6ejY6LMhOpQMluJV7w84Zc/YGr1MC+mJrllDYDB4P5aqRce5sFF5gxihNAtFl3H/iyTJWnUr10aEaGR5scLJPfVDdQ6pTvb7a5qqnQv6kQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=jvtJGvHf; 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="jvtJGvHf" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9E5491F000E9; Thu, 28 May 2026 20:20:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779999647; bh=V2q4ewP0hytKIXtZApw8WKHxvyeqU30ZPRxQQe9/EzM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=jvtJGvHf/sUFvhn4/d99SLqiMtiyF4HlHapxQYc2MPLTZyLHiNDMMiixYpriYYw3t J41xRXK+DTvpaW+UNLSh5T37LtCe0g2wKr2ZsGD66og1J3gUtqUZZdULPIvSuHRhur 1TuYTmyNlb2NMjErFBUIkrt5t4I8YxPgzYA8ckCk= 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 6.18 141/377] batman-adv: mcast: fix use-after-free in orig_node RCU release Date: Thu, 28 May 2026 21:46:19 +0200 Message-ID: <20260528194642.456544358@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260528194638.371537336@linuxfoundation.org> References: <20260528194638.371537336@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.18-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 @@ -835,8 +835,6 @@ 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); @@ -887,6 +885,8 @@ void batadv_orig_node_release(struct kre } spin_unlock_bh(&orig_node->vlan_list_lock); + batadv_mcast_purge_orig(orig_node); + call_rcu(&orig_node->rcu, batadv_orig_node_free_rcu); }