From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 616E230F8E for ; Wed, 20 Sep 2023 12:17:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id DFAE8C433CD; Wed, 20 Sep 2023 12:17:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695212250; bh=LqHDISMVcuf9c7sjRbkeJJFK0qfOqbusGKZwEo2Zpi4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=AP+6pKtYHO/jdTVCQY1hZ/BTrCSEAGxjxJw6eX7TQe3IZPb8puSKtHdM0ZiLTWYfw 96d149+QI3YwHkor/HgSCAOfKIR+KE+IkSBDJynxpY3FguKDUPYxQbmf/Y4NTM5IYK CLlq7IcnWAkGXHiohJ+BCkYMJSm/22h+NuU9GGH4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Eric Dumazet , David Laight , Kyle Zeng , Simon Horman , "David S. Miller" Subject: [PATCH 4.19 165/273] igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU Date: Wed, 20 Sep 2023 13:30:05 +0200 Message-ID: <20230920112851.619921804@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112846.440597133@linuxfoundation.org> References: <20230920112846.440597133@linuxfoundation.org> User-Agent: quilt/0.67 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 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet commit c3b704d4a4a265660e665df51b129e8425216ed1 upstream. This is a follow up of commit 915d975b2ffa ("net: deal with integer overflows in kmalloc_reserve()") based on David Laight feedback. Back in 2010, I failed to realize malicious users could set dev->mtu to arbitrary values. This mtu has been since limited to 0x7fffffff but regardless of how big dev->mtu is, it makes no sense for igmpv3_newpack() to allocate more than IP_MAX_MTU and risk various skb fields overflows. Fixes: 57e1ab6eaddc ("igmp: refine skb allocations") Link: https://lore.kernel.org/netdev/d273628df80f45428e739274ab9ecb72@AcuMS.aculab.com/ Signed-off-by: Eric Dumazet Reported-by: David Laight Cc: Kyle Zeng Reviewed-by: Simon Horman Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv4/igmp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -357,8 +357,9 @@ static struct sk_buff *igmpv3_newpack(st struct flowi4 fl4; int hlen = LL_RESERVED_SPACE(dev); int tlen = dev->needed_tailroom; - unsigned int size = mtu; + unsigned int size; + size = min(mtu, IP_MAX_MTU); while (1) { skb = alloc_skb(size + hlen + tlen, GFP_ATOMIC | __GFP_NOWARN);