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 7C23A1DED4F; Mon, 6 Jan 2025 15:46:43 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736178403; cv=none; b=SEwi8Ch5h6FVqVEasyZ3+YLtnaxri1/tg/MhiENWZvF6vw1Yzu4QlM6HyatZ5IQ7/rzCKuQwgjfuG7L4oYzBNOq10NquBnIDWGdjaZbNDmoUtuS8HlCYJTtITDTyzuItSG1M2anuULcxmqZZfofSQUz4GYcF47dNX+xWQ5XtW34= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736178403; c=relaxed/simple; bh=cqJolVxgOaZVe/5eyIs9pcbTYbEvv5WyvNpJhEC8uMQ=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZMEo+YLjL78nIMdcE7l8bDUveG8LA/4/MadveuIR8xhDQcrnMN4tVC7lRIeb9MEZ220TduJKknaS+l3u2io/iWlE7KVro4qP1k2e2z137kC7mlNO4wRKAZ5a1pPxGLkZheGqnYnmQ4FljuHmmnOk/doqHPk/DH9OuBAjwxad+Sw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=vFtaEDsi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="vFtaEDsi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0029EC4CED2; Mon, 6 Jan 2025 15:46:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1736178403; bh=cqJolVxgOaZVe/5eyIs9pcbTYbEvv5WyvNpJhEC8uMQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vFtaEDsigw0iX7FeQY0hCveyF5Kq2H2bpSrTsmkIQ5sKAKs9fPReqeLYfH2Fbq54A fCygEp59W/So3PK2CFhjDeCsvC+mIqq3niCcvJJSlHLTV4GiaafghLPIM4VB1AJdIU 9nI1PgN7izY+fvAN1di8icQ/BjLPAC9u/65XmjYQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Nikita Marushkin , Ilya Shchipletsov , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.10 106/138] netrom: check buffer length before accessing it Date: Mon, 6 Jan 2025 16:17:10 +0100 Message-ID: <20250106151137.244399498@linuxfoundation.org> X-Mailer: git-send-email 2.47.1 In-Reply-To: <20250106151133.209718681@linuxfoundation.org> References: <20250106151133.209718681@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org 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: Ilya Shchipletsov [ Upstream commit a4fd163aed2edd967a244499754dec991d8b4c7d ] Syzkaller reports an uninit value read from ax25cmp when sending raw message through ieee802154 implementation. ===================================================== BUG: KMSAN: uninit-value in ax25cmp+0x3a5/0x460 net/ax25/ax25_addr.c:119 ax25cmp+0x3a5/0x460 net/ax25/ax25_addr.c:119 nr_dev_get+0x20e/0x450 net/netrom/nr_route.c:601 nr_route_frame+0x1a2/0xfc0 net/netrom/nr_route.c:774 nr_xmit+0x5a/0x1c0 net/netrom/nr_dev.c:144 __netdev_start_xmit include/linux/netdevice.h:4940 [inline] netdev_start_xmit include/linux/netdevice.h:4954 [inline] xmit_one net/core/dev.c:3548 [inline] dev_hard_start_xmit+0x247/0xa10 net/core/dev.c:3564 __dev_queue_xmit+0x33b8/0x5130 net/core/dev.c:4349 dev_queue_xmit include/linux/netdevice.h:3134 [inline] raw_sendmsg+0x654/0xc10 net/ieee802154/socket.c:299 ieee802154_sock_sendmsg+0x91/0xc0 net/ieee802154/socket.c:96 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] kmem_cache_alloc_node+0x5e9/0xb10 mm/slub.c:3523 kmalloc_reserve+0x13d/0x4a0 net/core/skbuff.c:560 __alloc_skb+0x318/0x740 net/core/skbuff.c:651 alloc_skb include/linux/skbuff.h:1286 [inline] alloc_skb_with_frags+0xc8/0xbd0 net/core/skbuff.c:6334 sock_alloc_send_pskb+0xa80/0xbf0 net/core/sock.c:2780 sock_alloc_send_skb include/net/sock.h:1884 [inline] raw_sendmsg+0x36d/0xc10 net/ieee802154/socket.c:282 ieee802154_sock_sendmsg+0x91/0xc0 net/ieee802154/socket.c:96 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] ____sys_sendmsg+0x9c2/0xd60 net/socket.c:2584 ___sys_sendmsg+0x28d/0x3c0 net/socket.c:2638 __sys_sendmsg net/socket.c:2667 [inline] __do_sys_sendmsg net/socket.c:2676 [inline] __se_sys_sendmsg net/socket.c:2674 [inline] __x64_sys_sendmsg+0x307/0x490 net/socket.c:2674 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0x44/0x110 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x63/0x6b CPU: 0 PID: 5037 Comm: syz-executor166 Not tainted 6.7.0-rc7-syzkaller-00003-gfbafc3e621c3 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 ===================================================== This issue occurs because the skb buffer is too small, and it's actual allocation is aligned. This hides an actual issue, which is that nr_route_frame does not validate the buffer size before using it. Fix this issue by checking skb->len before accessing any fields in skb->data. Found by Linux Verification Center (linuxtesting.org) with Syzkaller. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Co-developed-by: Nikita Marushkin Signed-off-by: Nikita Marushkin Signed-off-by: Ilya Shchipletsov Link: https://patch.msgid.link/20241219082308.3942-1-rabbelkin@mail.ru Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/netrom/nr_route.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/net/netrom/nr_route.c b/net/netrom/nr_route.c index 9269b5e69b9a..8e15a0c96614 100644 --- a/net/netrom/nr_route.c +++ b/net/netrom/nr_route.c @@ -751,6 +751,12 @@ int nr_route_frame(struct sk_buff *skb, ax25_cb *ax25) int ret; struct sk_buff *skbn; + /* + * Reject malformed packets early. Check that it contains at least 2 + * addresses and 1 byte more for Time-To-Live + */ + if (skb->len < 2 * sizeof(ax25_address) + 1) + return 0; nr_src = (ax25_address *)(skb->data + 0); nr_dest = (ax25_address *)(skb->data + 7); -- 2.39.5