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 515663DDB03; Tue, 21 Jul 2026 22:50:18 +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=1784674219; cv=none; b=HEPVuFLOe73xWwxO+jqSZzrlHnZhs3Cb1Dqz6ccGI3CJVv4d/6/dXsHPfil/hzNJoWzGUY+W53VE3JAOeGs3v5nACyLPu7It2TgZLUkrcKkNewP7DHwIJe0J8mjSTLxTT9R+t6G9zPIUU4x74y5pmpGn7UsFrjXNpzbpq0xOGfo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784674219; c=relaxed/simple; bh=8etBJ8b7hys9+aRwNLHlTlct+6quhyrFUWeK9dDqgHQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=csv+gyV+jJcuWzFTn/XN+1ruq5IErG7cs1PMiuEe42HzWGspw0Fdg2RmEOfcBc6OqOtiEBG7/YgsxjwP5sOcWmEmZU3DyFDuUE8lKVoFx7CkCMwWSIzTMKlY4OYKMB+3YfdnUBEBtQCgOcP/KZbWqn2lgRrn6E2O6rl+bFDz6h8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TpMsq820; 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="TpMsq820" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B73481F000E9; Tue, 21 Jul 2026 22:50:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784674218; bh=kEMf3igTe8f2n8tdGDxAdI1n7aOdpCw5nGu43f7ZIbQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TpMsq8207cn4kD8TgDp+sc8BGJOfdxYlHTnkbW7YdwpgGD9a9IiWqxjfrcwLkkUnV Mh73La9SV0EaRMs2m11LdClTrZ/7tmjraGN/vxC3jkreo6QR8M4lgZnan4hjXfOVwV uSeZ11AAWGR6fnoIBrbXNGmQmQ3dtOq3evpTP9kU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Sven Eckelmann Subject: [PATCH 5.10 459/699] batman-adv: gw: acquire ethernet header only after skb realloc Date: Tue, 21 Jul 2026 17:23:38 +0200 Message-ID: <20260721152406.052644163@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260721152355.667394603@linuxfoundation.org> References: <20260721152355.667394603@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 5.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Sven Eckelmann commit 77880a3be88d378d60cc1e8f8ec70430e2ed0518 upstream. The pskb_may_pull() called by batadv_get_vid() could reallocate the buffer behind the skb. Variables which were pointing to the old buffer need to be reassigned to avoid an use-after-free. Cc: stable@vger.kernel.org Fixes: 6c413b1c22a2 ("batman-adv: send every DHCP packet as bat-unicast") Signed-off-by: Sven Eckelmann Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/gateway_client.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/batman-adv/gateway_client.c +++ b/net/batman-adv/gateway_client.c @@ -741,12 +741,13 @@ bool batadv_gw_out_of_range(struct batad struct batadv_gw_node *gw_node = NULL; struct batadv_gw_node *curr_gw = NULL; struct batadv_neigh_ifinfo *curr_ifinfo, *old_ifinfo; - struct ethhdr *ethhdr = (struct ethhdr *)skb->data; + struct ethhdr *ethhdr; bool out_of_range = false; u8 curr_tq_avg; unsigned short vid; vid = batadv_get_vid(skb, 0); + ethhdr = (struct ethhdr *)skb->data; if (is_multicast_ether_addr(ethhdr->h_dest)) goto out;