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 6E499223328; Thu, 28 May 2026 20:37:36 +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=1780000657; cv=none; b=smX+RuvkT9jfE+HFvhUvtJ9VULOAWgA/a/s4fy3bwmFsbIHU6s1URYPShwBGeWCSqG+DjjDcbYfUDAuTx4FRQBB6QydlF+2Vm/oVmT3PpnIPiRfrFddVV0jZk0qrw18MGoT2XgyFXP4NUOtrxCuKoVO2CgrhQ1PsBsANETjEZyI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780000657; c=relaxed/simple; bh=SUmVYHpBCPuvmhc5+YSU8kCI8p8r7xdsr5YDk5pDudM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ksWZbxeUYG55KV9zbtpgRHsmVlTY50DT493IpvCpetp4cQjMjhLVhzRTZj62pD//avZxwJLmHrQ5ptTBmnsA6GtyMxo6x0f+yflBrupIoY4zbw09cmiEpQqaT+otz1m9ZFQdikkK0du5rLIcU+gcrQm+Iii3p+uEhTphD3wWFT0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gjMbdZDa; 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="gjMbdZDa" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 967011F000E9; Thu, 28 May 2026 20:37:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1780000656; bh=YPo6U5MiiAJCnclikJHL/NTrBowTVVDEHUtBiEVstgI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gjMbdZDapIgl+7EKs/fSch5kGQvm+DjEjqQQ8WA46TOZBnRcgpcYi+BC/eoyTImpW KvXfr4AKtnnw6zBCn60J9UfiGcAcK9A0ir84EJh0AzxU6Mrn2LBRylUe6DA5yyCCbf 2G31/lIIIrCtOhCvFET3pTn+c0i3cqnM6qXbSoeI= 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 6.12 121/272] batman-adv: mcast: fix use-after-free in orig_node RCU release Date: Thu, 28 May 2026 21:48:15 +0200 Message-ID: <20260528194632.767355030@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260528194629.379955525@linuxfoundation.org> References: <20260528194629.379955525@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 6.12-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 @@ -850,8 +850,6 @@ 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); @@ -905,6 +903,8 @@ 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); }