From patchwork Fri Apr 19 14:42:13 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bethany Jamison X-Patchwork-Id: 1925570 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ubuntu.com (client-ip=185.125.189.65; helo=lists.ubuntu.com; envelope-from=kernel-team-bounces@lists.ubuntu.com; receiver=patchwork.ozlabs.org) Received: from lists.ubuntu.com (lists.ubuntu.com [185.125.189.65]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4VLcn61wmQz1yPJ for ; Sat, 20 Apr 2024 00:42:34 +1000 (AEST) Received: from localhost ([127.0.0.1] helo=lists.ubuntu.com) by lists.ubuntu.com with esmtp (Exim 4.86_2) (envelope-from ) id 1rxpRb-0001Yc-V6; Fri, 19 Apr 2024 14:42:27 +0000 Received: from smtp-relay-internal-0.internal ([10.131.114.225] helo=smtp-relay-internal-0.canonical.com) by lists.ubuntu.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1rxpRY-0001Vx-Pl for kernel-team@lists.ubuntu.com; Fri, 19 Apr 2024 14:42:24 +0000 Received: from mail-io1-f71.google.com (mail-io1-f71.google.com [209.85.166.71]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by smtp-relay-internal-0.canonical.com (Postfix) with ESMTPS id 668C53F16A for ; Fri, 19 Apr 2024 14:42:24 +0000 (UTC) Received: by mail-io1-f71.google.com with SMTP id ca18e2360f4ac-7d676654758so232969139f.3 for ; Fri, 19 Apr 2024 07:42:24 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713537743; x=1714142543; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=P2qhzws5JWch1gPp/S4WkUPbCG2diAWc7+eIUxvO5JI=; b=FmErBi2DH0MAXagO3MHdEAwtwp3KE/gYVaXTJCnRWsH1Xiiochh37jf8hFbY+RWqcs iy8L6dU+LkNb8/h0rXLi3O+ZcfE5WN3wQVpS6fgi6xhezp0OW6J9KvlwNvCOxfxSqvLK LC/PbvKu//gom6a2+l2AG8jgk5hpEE0xfj4oeDX5bo0H3QdtUgi30oqCvwKul6b9peB1 bqmquYQlaoxkuWrtvzVCtipNBWSpsWRRIBReeG2Ae6ygax2it6mLFM6zR58BbfLQu1qW Y8NmRZEHymgj/sDz4xKgVSe1YFcdJwaDPcBo2yYOBB0aJc2JTEyqyMDqC5BUl7bHYh2F OwEw== X-Gm-Message-State: AOJu0YyBjse+0kQ04ySES9uKr+rkMvFtDQEa4obeUVnbxM9Q0MStnqXp gb27RTCeOBQK9MZzVSmwwoUCplz9wBYUEzAKNKcv0bivnT0Oy5L6dHiGT38pj4S0psRLff/reYi ldh9dmZ3hTZCWB5AHGV46donFUBf4awuTnCls2RQ8PiZNxBJitvFDuBCJLcHfGE2c2w2M7xVlgG 0uF9OCqpqyTYxl X-Received: by 2002:a5e:c746:0:b0:7d5:df1d:2562 with SMTP id g6-20020a5ec746000000b007d5df1d2562mr3129668iop.14.1713537743007; Fri, 19 Apr 2024 07:42:23 -0700 (PDT) X-Google-Smtp-Source: AGHT+IEp6iO5lGvpCL9igi4mVrCwstF3Gk5VgBLjAHz+Vrkof/khv4xpGyiYIQviT4TdMEVmsWpMBA== X-Received: by 2002:a5e:c746:0:b0:7d5:df1d:2562 with SMTP id g6-20020a5ec746000000b007d5df1d2562mr3129572iop.14.1713537741597; Fri, 19 Apr 2024 07:42:21 -0700 (PDT) Received: from smtp.gmail.com (104-218-69-129.dynamic.lnk.ne.allofiber.net. [104.218.69.129]) by smtp.gmail.com with ESMTPSA id i10-20020a05663813ca00b00482d033889csm1089235jaj.171.2024.04.19.07.42.21 for (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 19 Apr 2024 07:42:21 -0700 (PDT) From: Bethany Jamison To: kernel-team@lists.ubuntu.com Subject: [SRU][M][PATCH 1/1] arp: Prevent overflow in arp_req_get(). Date: Fri, 19 Apr 2024 09:42:13 -0500 Message-Id: <20240419144219.21413-2-bethany.jamison@canonical.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20240419144219.21413-1-bethany.jamison@canonical.com> References: <20240419144219.21413-1-bethany.jamison@canonical.com> MIME-Version: 1.0 X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.20 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: "kernel-team" From: Kuniyuki Iwashima [ Upstream commit a7d6027790acea24446ddd6632d394096c0f4667 ] syzkaller reported an overflown write in arp_req_get(). [0] When ioctl(SIOCGARP) is issued, arp_req_get() looks up an neighbour entry and copies neigh->ha to struct arpreq.arp_ha.sa_data. The arp_ha here is struct sockaddr, not struct sockaddr_storage, so the sa_data buffer is just 14 bytes. In the splat below, 2 bytes are overflown to the next int field, arp_flags. We initialise the field just after the memcpy(), so it's not a problem. However, when dev->addr_len is greater than 22 (e.g. MAX_ADDR_LEN), arp_netmask is overwritten, which could be set as htonl(0xFFFFFFFFUL) in arp_ioctl() before calling arp_req_get(). To avoid the overflow, let's limit the max length of memcpy(). Note that commit b5f0de6df6dc ("net: dev: Convert sa_data to flexible array in struct sockaddr") just silenced syzkaller. [0]: memcpy: detected field-spanning write (size 16) of single field "r->arp_ha.sa_data" at net/ipv4/arp.c:1128 (size 14) WARNING: CPU: 0 PID: 144638 at net/ipv4/arp.c:1128 arp_req_get+0x411/0x4a0 net/ipv4/arp.c:1128 Modules linked in: CPU: 0 PID: 144638 Comm: syz-executor.4 Not tainted 6.1.74 #31 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.0-debian-1.16.0-5 04/01/2014 RIP: 0010:arp_req_get+0x411/0x4a0 net/ipv4/arp.c:1128 Code: fd ff ff e8 41 42 de fb b9 0e 00 00 00 4c 89 fe 48 c7 c2 20 6d ab 87 48 c7 c7 80 6d ab 87 c6 05 25 af 72 04 01 e8 5f 8d ad fb <0f> 0b e9 6c fd ff ff e8 13 42 de fb be 03 00 00 00 4c 89 e7 e8 a6 RSP: 0018:ffffc900050b7998 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff88803a815000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8641a44a RDI: 0000000000000001 RBP: ffffc900050b7a98 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 203a7970636d656d R12: ffff888039c54000 R13: 1ffff92000a16f37 R14: ffff88803a815084 R15: 0000000000000010 FS: 00007f172bf306c0(0000) GS:ffff88805aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f172b3569f0 CR3: 0000000057f12005 CR4: 0000000000770ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: arp_ioctl+0x33f/0x4b0 net/ipv4/arp.c:1261 inet_ioctl+0x314/0x3a0 net/ipv4/af_inet.c:981 sock_do_ioctl+0xdf/0x260 net/socket.c:1204 sock_ioctl+0x3ef/0x650 net/socket.c:1321 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:870 [inline] __se_sys_ioctl fs/ioctl.c:856 [inline] __x64_sys_ioctl+0x18e/0x220 fs/ioctl.c:856 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x37/0x90 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x64/0xce RIP: 0033:0x7f172b262b8d Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f172bf300b8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f172b3abf80 RCX: 00007f172b262b8d RDX: 0000000020000000 RSI: 0000000000008954 RDI: 0000000000000003 RBP: 00007f172b2d3493 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f172b3abf80 R15: 00007f172bf10000 Reported-by: syzkaller Reported-by: Bjoern Doebel Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima Link: https://lore.kernel.org/r/20240215230516.31330-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin (cherry picked from commit a3f2c083cb575d80a7627baf3339e78fedccbb91 linux-6.6.y) CVE-2024-26733 Signed-off-by: Bethany Jamison --- net/ipv4/arp.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c index 9456f5bb35e5d..0d0d725b46ad0 100644 --- a/net/ipv4/arp.c +++ b/net/ipv4/arp.c @@ -1125,7 +1125,8 @@ static int arp_req_get(struct arpreq *r, struct net_device *dev) if (neigh) { if (!(READ_ONCE(neigh->nud_state) & NUD_NOARP)) { read_lock_bh(&neigh->lock); - memcpy(r->arp_ha.sa_data, neigh->ha, dev->addr_len); + memcpy(r->arp_ha.sa_data, neigh->ha, + min(dev->addr_len, sizeof(r->arp_ha.sa_data_min))); r->arp_flags = arp_state_to_flags(neigh); read_unlock_bh(&neigh->lock); r->arp_ha.sa_family = dev->type;