From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from ganesha.gnumonks.org (ganesha.gnumonks.org [213.95.27.120]) (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 3742BC8D1 for ; Fri, 9 Aug 2024 08:00:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.27.120 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723190410; cv=none; b=TKowFDsC0AzY+0wli5FzPiVWauUz0lnvjJZcXhwHXEteSnCI8upVa4yZJXnBXATqjGfBCqzkhoZjUNg8RvhP3jX47wLRbqjzp8NuqEutqZCDamZTP+15U5dkjTePNdx+lOomCRLqaoXCbROo0sFht2Vsn8Hx2oJzQBQB4qEFLog= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1723190410; c=relaxed/simple; bh=RoPdvsYEFl36YioiyL3Yrz2txiM5pG4P5zpSgwteBAc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=VLens2MSdGMpj68WeyPA6Rq6+LGR4SFB5Mm+oekJzjBrN23SgJMjoWi8kmYoAbpw2MTlGMP/XBhJW7mw7gvPtyQNW2IfzLhtvBEhDhXdcV4CCFTyjc0ThYii1VW4k+cICJO7BwQb0eUkNjb6e1l09guRfo9d2uxbOaEGG0+GiUM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org; spf=pass smtp.mailfrom=gnumonks.org; arc=none smtp.client-ip=213.95.27.120 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=netfilter.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gnumonks.org Received: from [46.222.110.9] (port=3150 helo=gnumonks.org) by ganesha.gnumonks.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1scKXR-007jcX-Qk; Fri, 09 Aug 2024 09:59:56 +0200 Date: Fri, 9 Aug 2024 09:59:51 +0200 From: Pablo Neira Ayuso To: Eric Dumazet Cc: "David S . Miller" , Jakub Kicinski , Paolo Abeni , netdev@vger.kernel.org, eric.dumazet@gmail.com, Harald Welte Subject: Re: [PATCH net] gtp: pull network headers in gtp_dev_xmit() Message-ID: References: <20240808132455.3413916-1-edumazet@google.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240808132455.3413916-1-edumazet@google.com> X-Spam-Score: -1.7 (-) On Thu, Aug 08, 2024 at 01:24:55PM +0000, Eric Dumazet wrote: > syzbot/KMSAN reported use of uninit-value in get_dev_xmit() [1] > > We must make sure the IPv4 or Ipv6 header is pulled in skb->head > before accessing fields in them. > > Use pskb_inet_may_pull() to fix this issue. > > [1] > BUG: KMSAN: uninit-value in ipv6_pdp_find drivers/net/gtp.c:220 [inline] > BUG: KMSAN: uninit-value in gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline] > BUG: KMSAN: uninit-value in gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281 > ipv6_pdp_find drivers/net/gtp.c:220 [inline] > gtp_build_skb_ip6 drivers/net/gtp.c:1229 [inline] > gtp_dev_xmit+0x1424/0x2540 drivers/net/gtp.c:1281 > __netdev_start_xmit include/linux/netdevice.h:4913 [inline] > netdev_start_xmit include/linux/netdevice.h:4922 [inline] > xmit_one net/core/dev.c:3580 [inline] > dev_hard_start_xmit+0x247/0xa20 net/core/dev.c:3596 > __dev_queue_xmit+0x358c/0x5610 net/core/dev.c:4423 > dev_queue_xmit include/linux/netdevice.h:3105 [inline] > packet_xmit+0x9c/0x6c0 net/packet/af_packet.c:276 > packet_snd net/packet/af_packet.c:3145 [inline] > packet_sendmsg+0x90e3/0xa3a0 net/packet/af_packet.c:3177 > sock_sendmsg_nosec net/socket.c:730 [inline] > __sock_sendmsg+0x30f/0x380 net/socket.c:745 > __sys_sendto+0x685/0x830 net/socket.c:2204 > __do_sys_sendto net/socket.c:2216 [inline] > __se_sys_sendto net/socket.c:2212 [inline] > __x64_sys_sendto+0x125/0x1d0 net/socket.c:2212 > x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > Uninit was created at: > slab_post_alloc_hook mm/slub.c:3994 [inline] > slab_alloc_node mm/slub.c:4037 [inline] > kmem_cache_alloc_node_noprof+0x6bf/0xb80 mm/slub.c:4080 > kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:583 > __alloc_skb+0x363/0x7b0 net/core/skbuff.c:674 > alloc_skb include/linux/skbuff.h:1320 [inline] > alloc_skb_with_frags+0xc8/0xbf0 net/core/skbuff.c:6526 > sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2815 > packet_alloc_skb net/packet/af_packet.c:2994 [inline] > packet_snd net/packet/af_packet.c:3088 [inline] > packet_sendmsg+0x749c/0xa3a0 net/packet/af_packet.c:3177 > sock_sendmsg_nosec net/socket.c:730 [inline] > __sock_sendmsg+0x30f/0x380 net/socket.c:745 > __sys_sendto+0x685/0x830 net/socket.c:2204 > __do_sys_sendto net/socket.c:2216 [inline] > __se_sys_sendto net/socket.c:2212 [inline] > __x64_sys_sendto+0x125/0x1d0 net/socket.c:2212 > x64_sys_call+0x3799/0x3c10 arch/x86/include/generated/asm/syscalls_64.h:45 > do_syscall_x64 arch/x86/entry/common.c:52 [inline] > do_syscall_64+0xcd/0x1e0 arch/x86/entry/common.c:83 > entry_SYSCALL_64_after_hwframe+0x77/0x7f > > CPU: 0 UID: 0 PID: 7115 Comm: syz.1.515 Not tainted 6.11.0-rc1-syzkaller-00043-g94ede2a3e913 #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 > > Fixes: 999cb275c807 ("gtp: add IPv6 support") > Fixes: 459aa660eb1d ("gtp: add initial driver for datapath of GPRS Tunneling Protocol (GTP-U)") > Signed-off-by: Eric Dumazet Reviewed-by: Pablo Neira Ayuso Thanks.