From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794591074; b=zRNsPrabnL78G/dy9ww6DrCoWmwlyfignPSYFpUGm6Bx0loNUYsmtsL6OpuLKLUhRYnX gCBd/ElXA8tqaqs+9eBdlFzKB7S3AWBcL9Mojx+wS59rHFGCjLz9BTQNGGKvv6+g+IZrn oYGBdsY9KNNotOl+e+sbDHQ/UNjHPWX0G5XJc7q1xLBKrjGi0kCq7fSCPzP5Q1T6yzQfo YT8yjYgUXx1DPuAaG5gcwhd6LRbEYvhAAzk3lTNEHvwN6eBW0jZ0iDXafsZ9zkdaioAXR VmCAT186licpJKnv7QzWMs+O2Ml7nGxgMSF0gTuNUP7UbEo7udnshttm0KnRDDirsNQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794591074; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=7rQfuMN8ckmKdoMYDGtqDwwIXd+i5ienvYA3Rp3qRBc=; b=5jPUfDEA34CVj7TE7enieM/OjHBviszs/h+Q7AGpgASwTuLNLntJYFLdCSsPHf8eYpve +dFDiEV/HIFq7ZzmLg0HMgXuqGMXEhnP7pQoUQbpK/JoaeTQxRnh3k588VO/PVP8fpNsf wGu4Vcf5wXgTAlgT2cWnYK/KS4rwHsD/dp8U+mFawtdc46e464rgJeXspkWY/0E+E84XR 5xpWHM8zfzVBrXMIv/pbs8yDdV+GWmoYd2F5bye6qhPxoVu8tQz/5bxKqMMDmm5bxjePK WX5r/GLSVVqiT6T7+YuuKeaj/o0Nb+sZKaBw6pwQpphtO/roloqv+5HYvHjTHlCl8yg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=Fjp05rlU; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3DC59607143A; Fri, 13 Nov 2026 17:31:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=Fjp05rlU Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC60B1F000C7; Fri, 13 Nov 2026 17:31:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794591074; bh=7rQfuMN8ckmKdoMYDGtqDwwIXd+i5ienvYA3Rp3qRBc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=Fjp05rlUIIyA8mrzEMMAr4uBwP5X779AhVT0twsETMyclJVpJnluNqXmgQ6oQWH2s gxw/kDbX/tG4kTDUeVZfmxv63wWJNiF9BWnBBaDsDa9MGApiFLJnd0O0VyqrqwJ2aj KqnVG6p77EqeICSt5LmtCrqzYh50GIbuj2OwAgug= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kyle Zeng , Sven Eckelmann , Sasha Levin Subject: [PATCH 6.12 195/670] batman-adv: mcast: validate tracker padding before forwarding Date: Fri, 13 Nov 2026 10:45:59 -0500 Message-ID: <20261113153818.600751689@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261113153811.177190860@linuxfoundation.org> References: <20261113153811.177190860@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kyle Zeng [ Upstream commit ea01fff30f631e67ee5f0a2b97855d772b3a35fc ] A multicast tracker with an even number of destinations needs two padding bytes after its destination list. batadv_mcast_forw_packet() currently only checks that the count field and the addresses fit in the tracker TVLV. If an unpadded even tracker is compacted to an odd number of destinations, batadv_mcast_forw_shrink_update_headers() includes those missing padding bytes in the amount to remove. The subsequent memmove can then write two bytes past the old packet tail. With no tailroom, this corrupts skb_shared_info. Include the required padding in the existing tracker length check. This rejects the malformed tracker before either received or locally generated packets can reach the compactor. Fixes: 2dfe644a1ce0 ("batman-adv: mcast: shrink tracker packet after scrubbing") Cc: stable@vger.kernel.org Signed-off-by: Kyle Zeng Signed-off-by: Sven Eckelmann Signed-off-by: Sasha Levin --- net/batman-adv/multicast_forw.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/net/batman-adv/multicast_forw.c b/net/batman-adv/multicast_forw.c index 893cb9ce9971c..9752e3dd79ef3 100644 --- a/net/batman-adv/multicast_forw.c +++ b/net/batman-adv/multicast_forw.c @@ -950,8 +950,11 @@ static int batadv_mcast_forw_packet(struct batadv_priv *bat_priv, dest = (u8 *)mcast_tracker + sizeof(*mcast_tracker); - /* check if full tracker tvlv is within skb length */ + /* check if full tracker tvlv, including padding, is within skb length */ tvlv_len = sizeof(*mcast_tracker) + ETH_ALEN * num_dests; + if (!(num_dests % 2)) + tvlv_len += 2; + if (tvlv_len > skb_network_header_len(skb)) return -EINVAL; -- 2.53.0