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 51A5F443A81; Tue, 21 Jul 2026 22:23:28 +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=1784672609; cv=none; b=t+yJeZ5i4YOERtsYFOqi91ytgZ1bQZF1GVwr+k9wMpGJUo3H9JWCH+Nxqdo7vUSKT6H7dSfC50gZzRu5txzFQXJmR9V5hFzDYoWzCrka+FnfCCbEVEE4JtMFd6Gn+GxK3wlHSWhuP/9plWzmVqdw7bLgE38XIZEPCrIvJQ8DZvI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784672609; c=relaxed/simple; bh=9LHooJxn5H1ZItFJgGAnwE+edpVa0oxPy7edzdSFNSc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hlq7B+kK9o6k8FtiICOo2XgejNmfbOtq1lFJG0tpH3tVws4R1jKK+0vraH6Fv9ajnovQT3443u3uMXIqXqA91XAYKwew+LVgrPytXbOjFvkOmZeBrJqvjkp1Gq6vUJvDAKceJm/6BhDZ8nvldzT+Td7fipGFVm5M0ZKleejYjxI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FKzzfCtK; 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="FKzzfCtK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B76241F000E9; Tue, 21 Jul 2026 22:23:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784672608; bh=6zzIXBlGr2lT6l9eiYoxGuc2lR+VKhNyzv0sN/w6qTY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FKzzfCtKycGt67sQMJeQPtdLNwB3kNZTBC9U4S/C/umCcrNk1LjFcp//wmffhbRro KRYiLiEcn/kxzxmZekzVPPWiCT9dptoKvZcrpo/VEJcK6bCAyl1gOIop2OkNiIHuWq m3tEwdGEgSs+ITNPFq6OnFGNWUh63aDFJ4v6o1Vs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sashiko , Sven Eckelmann , Sasha Levin Subject: [PATCH 5.15 690/843] batman-adv: ensure minimal ethernet header on TX Date: Tue, 21 Jul 2026 17:25:25 +0200 Message-ID: <20260721152421.575895533@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152405.946368001@linuxfoundation.org> References: <20260721152405.946368001@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit 49df66b7993c80b80c7eb9a84ba5b3410c8296a0 upstream. As documented in commit 8bd67ebb50c0 ("net: bridge: xmit: make sure we have at least eth header len bytes"), it is possible by for a local user with eBPF TC hook access to attach a tc filter which truncates the packet and redirects to an batadv interface. But the code assumes that at least ETH_HLEN bytes are available and thus might read outside of the available buffer. The batadv_interface_tx() must therefore always check itself if enough data is available for the ethernet header and don't rely on min_header_len. Cc: stable@vger.kernel.org Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol") Reported-by: Sashiko [ move from mesh- to soft-interface.c ] Signed-off-by: Sven Eckelmann Signed-off-by: Sasha Levin --- net/batman-adv/soft-interface.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/batman-adv/soft-interface.c b/net/batman-adv/soft-interface.c index 21297af54e4ea7..bdd6dd7fa77588 100644 --- a/net/batman-adv/soft-interface.c +++ b/net/batman-adv/soft-interface.c @@ -208,6 +208,9 @@ static netdev_tx_t batadv_interface_tx(struct sk_buff *skb, if (atomic_read(&bat_priv->mesh_state) != BATADV_MESH_ACTIVE) goto dropped; + if (!pskb_may_pull(skb, ETH_HLEN)) + goto dropped; + /* reset control block to avoid left overs from previous users */ memset(skb->cb, 0, sizeof(struct batadv_skb_cb)); -- 2.53.0