Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D084AC433EF for ; Wed, 1 Dec 2021 02:00:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345775AbhLACDe (ORCPT ); Tue, 30 Nov 2021 21:03:34 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45694 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1345519AbhLACDc (ORCPT ); Tue, 30 Nov 2021 21:03:32 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF042C061574; Tue, 30 Nov 2021 18:00:11 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id B834CB81C48; Wed, 1 Dec 2021 02:00:10 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPS id 5E979C53FCB; Wed, 1 Dec 2021 02:00:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1638324009; bh=687/kwpPzBHMaCE2+p5sffdjqQ2Gjf4AVcYUBOFeQ7g=; h=Subject:From:Date:References:In-Reply-To:To:Cc:From; b=YD5aMPAWJ6+EdHU44yVxvg9ITWJzhwhmTzrB6uXknW05/udTznuioGUQNwjyu6o3d 5NdDU01rfxA5lr3cd3dqsUABTd6R1Obu5/rSEsG5NzyYYBGonVNLs2tBWN1FE8e3SA 68TH6MvEzZv4ALsfrfkhs7YWT0iTwHgYgXj3gkkb8zI56trsx2h6N28X9zJ2EqHJas yqVALTShQJkzYJEHUIM0jUZ1Fv6uFfRhHRjZbI71GwKiRU4bChNkDLsP0fVP0bw70l XcF5mrcwR4FwTmJpWljksSxlu7IuWg9f61DqBR8q9GsVPd/f8MSvHYkg9sKkIGVlaz EK3BCsc2cJahg== Received: from pdx-korg-docbuild-2.ci.codeaurora.org (localhost.localdomain [127.0.0.1]) by pdx-korg-docbuild-2.ci.codeaurora.org (Postfix) with ESMTP id 38A5D60A38; Wed, 1 Dec 2021 02:00:09 +0000 (UTC) Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH v4] net: netlink: af_netlink: Prevent empty skb by adding a check on len. From: patchwork-bot+netdevbpf@kernel.org Message-Id: <163832400922.30071.9931042552498689425.git-patchwork-notify@kernel.org> Date: Wed, 01 Dec 2021 02:00:09 +0000 References: <20211129175328.55339-1-harshit.m.mogalapalli@oracle.com> In-Reply-To: <20211129175328.55339-1-harshit.m.mogalapalli@oracle.com> To: Harshit Mogalapalli Cc: ramanan.govindarajan@oracle.com, george.kennedy@oracle.com, vijayendra.suman@oracle.com, stephen@networkplumber.org, syzkaller@googlegroups.com, davem@davemloft.net, kuba@kernel.org, yajun.deng@linux.dev, dsahern@kernel.org, fw@strlen.de, marcelo.leitner@gmail.com, aahringo@redhat.com, edumazet@google.com, johannes.berg@intel.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hello: This patch was applied to netdev/net.git (master) by Jakub Kicinski : On Mon, 29 Nov 2021 09:53:27 -0800 you wrote: > Adding a check on len parameter to avoid empty skb. This prevents a > division error in netem_enqueue function which is caused when skb->len=0 > and skb->data_len=0 in the randomized corruption step as shown below. > > skb->data[prandom_u32() % skb_headlen(skb)] ^= 1<<(prandom_u32() % 8); > > Crash Report: > [ 343.170349] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family > 0 port 6081 - 0 > [ 343.216110] netem: version 1.3 > [ 343.235841] divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI > [ 343.236680] CPU: 3 PID: 4288 Comm: reproducer Not tainted 5.16.0-rc1+ > [ 343.237569] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), > BIOS 1.11.0-2.el7 04/01/2014 > [ 343.238707] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem] > [ 343.239499] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff > ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f > 74 f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03 > [ 343.241883] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246 > [ 343.242589] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX: > 0000000000000000 > [ 343.243542] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI: > ffff88800f8eda40 > [ 343.244474] RBP: ffff88800bcd7458 R08: 0000000000000000 R09: > ffffffff94fb8445 > [ 343.245403] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12: > 0000000000000000 > [ 343.246355] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15: > 0000000000000020 > [ 343.247291] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000) > knlGS:0000000000000000 > [ 343.248350] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 343.249120] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4: > 00000000000006e0 > [ 343.250076] Call Trace: > [ 343.250423] > [ 343.250713] ? memcpy+0x4d/0x60 > [ 343.251162] ? netem_init+0xa0/0xa0 [sch_netem] > [ 343.251795] ? __sanitizer_cov_trace_pc+0x21/0x60 > [ 343.252443] netem_enqueue+0xe28/0x33c0 [sch_netem] > [ 343.253102] ? stack_trace_save+0x87/0xb0 > [ 343.253655] ? filter_irq_stacks+0xb0/0xb0 > [ 343.254220] ? netem_init+0xa0/0xa0 [sch_netem] > [ 343.254837] ? __kasan_check_write+0x14/0x20 > [ 343.255418] ? _raw_spin_lock+0x88/0xd6 > [ 343.255953] dev_qdisc_enqueue+0x50/0x180 > [ 343.256508] __dev_queue_xmit+0x1a7e/0x3090 > [ 343.257083] ? netdev_core_pick_tx+0x300/0x300 > [ 343.257690] ? check_kcov_mode+0x10/0x40 > [ 343.258219] ? _raw_spin_unlock_irqrestore+0x29/0x40 > [ 343.258899] ? __kasan_init_slab_obj+0x24/0x30 > [ 343.259529] ? setup_object.isra.71+0x23/0x90 > [ 343.260121] ? new_slab+0x26e/0x4b0 > [ 343.260609] ? kasan_poison+0x3a/0x50 > [ 343.261118] ? kasan_unpoison+0x28/0x50 > [ 343.261637] ? __kasan_slab_alloc+0x71/0x90 > [ 343.262214] ? memcpy+0x4d/0x60 > [ 343.262674] ? write_comp_data+0x2f/0x90 > [ 343.263209] ? __kasan_check_write+0x14/0x20 > [ 343.263802] ? __skb_clone+0x5d6/0x840 > [ 343.264329] ? __sanitizer_cov_trace_pc+0x21/0x60 > [ 343.264958] dev_queue_xmit+0x1c/0x20 > [ 343.265470] netlink_deliver_tap+0x652/0x9c0 > [ 343.266067] netlink_unicast+0x5a0/0x7f0 > [ 343.266608] ? netlink_attachskb+0x860/0x860 > [ 343.267183] ? __sanitizer_cov_trace_pc+0x21/0x60 > [ 343.267820] ? write_comp_data+0x2f/0x90 > [ 343.268367] netlink_sendmsg+0x922/0xe80 > [ 343.268899] ? netlink_unicast+0x7f0/0x7f0 > [ 343.269472] ? __sanitizer_cov_trace_pc+0x21/0x60 > [ 343.270099] ? write_comp_data+0x2f/0x90 > [ 343.270644] ? netlink_unicast+0x7f0/0x7f0 > [ 343.271210] sock_sendmsg+0x155/0x190 > [ 343.271721] ____sys_sendmsg+0x75f/0x8f0 > [ 343.272262] ? kernel_sendmsg+0x60/0x60 > [ 343.272788] ? write_comp_data+0x2f/0x90 > [ 343.273332] ? write_comp_data+0x2f/0x90 > [ 343.273869] ___sys_sendmsg+0x10f/0x190 > [ 343.274405] ? sendmsg_copy_msghdr+0x80/0x80 > [ 343.274984] ? slab_post_alloc_hook+0x70/0x230 > [ 343.275597] ? futex_wait_setup+0x240/0x240 > [ 343.276175] ? security_file_alloc+0x3e/0x170 > [ 343.276779] ? write_comp_data+0x2f/0x90 > [ 343.277313] ? __sanitizer_cov_trace_pc+0x21/0x60 > [ 343.277969] ? write_comp_data+0x2f/0x90 > [ 343.278515] ? __fget_files+0x1ad/0x260 > [ 343.279048] ? __sanitizer_cov_trace_pc+0x21/0x60 > [ 343.279685] ? write_comp_data+0x2f/0x90 > [ 343.280234] ? __sanitizer_cov_trace_pc+0x21/0x60 > [ 343.280874] ? sockfd_lookup_light+0xd1/0x190 > [ 343.281481] __sys_sendmsg+0x118/0x200 > [ 343.281998] ? __sys_sendmsg_sock+0x40/0x40 > [ 343.282578] ? alloc_fd+0x229/0x5e0 > [ 343.283070] ? write_comp_data+0x2f/0x90 > [ 343.283610] ? write_comp_data+0x2f/0x90 > [ 343.284135] ? __sanitizer_cov_trace_pc+0x21/0x60 > [ 343.284776] ? ktime_get_coarse_real_ts64+0xb8/0xf0 > [ 343.285450] __x64_sys_sendmsg+0x7d/0xc0 > [ 343.285981] ? syscall_enter_from_user_mode+0x4d/0x70 > [ 343.286664] do_syscall_64+0x3a/0x80 > [ 343.287158] entry_SYSCALL_64_after_hwframe+0x44/0xae > [ 343.287850] RIP: 0033:0x7fdde24cf289 > [ 343.288344] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 > 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 8b 0d b7 db 2c 00 f7 d8 64 89 01 48 > [ 343.290729] RSP: 002b:00007fdde2bd6d98 EFLAGS: 00000246 ORIG_RAX: > 000000000000002e > [ 343.291730] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: > 00007fdde24cf289 > [ 343.292673] RDX: 0000000000000000 RSI: 00000000200000c0 RDI: > 0000000000000004 > [ 343.293618] RBP: 00007fdde2bd6e20 R08: 0000000100000001 R09: > 0000000000000000 > [ 343.294557] R10: 0000000100000001 R11: 0000000000000246 R12: > 0000000000000000 > [ 343.295493] R13: 0000000000021000 R14: 0000000000000000 R15: > 00007fdde2bd7700 > [ 343.296432] > [ 343.296735] Modules linked in: sch_netem ip6_vti ip_vti ip_gre ipip > sit ip_tunnel geneve macsec macvtap tap ipvlan macvlan 8021q garp mrp > hsr wireguard libchacha20poly1305 chacha_x86_64 poly1305_x86_64 > ip6_udp_tunnel udp_tunnel libblake2s blake2s_x86_64 libblake2s_generic > curve25519_x86_64 libcurve25519_generic libchacha xfrm_interface > xfrm6_tunnel tunnel4 veth netdevsim psample batman_adv nlmon dummy team > bonding tls vcan ip6_gre ip6_tunnel tunnel6 gre tun ip6t_rpfilter > ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set > ebtable_nat ebtable_broute ip6table_nat ip6table_mangle > ip6table_security ip6table_raw iptable_nat nf_nat nf_conntrack > nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_security > iptable_raw ebtable_filter ebtables rfkill ip6table_filter ip6_tables > iptable_filter ppdev bochs drm_vram_helper drm_ttm_helper ttm > drm_kms_helper cec parport_pc drm joydev floppy parport sg syscopyarea > sysfillrect sysimgblt i2c_piix4 qemu_fw_cfg fb_sys_fops pcspkr > [ 343.297459] ip_tables xfs virtio_net net_failover failover sd_mod > sr_mod cdrom t10_pi ata_generic pata_acpi ata_piix libata virtio_pci > virtio_pci_legacy_dev serio_raw virtio_pci_modern_dev dm_mirror > dm_region_hash dm_log dm_mod > [ 343.311074] Dumping ftrace buffer: > [ 343.311532] (ftrace buffer empty) > [ 343.312040] ---[ end trace a2e3db5a6ae05099 ]--- > [ 343.312691] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem] > [ 343.313481] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff > ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f > 74 f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03 > [ 343.315893] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246 > [ 343.316622] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX: > 0000000000000000 > [ 343.317585] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI: > ffff88800f8eda40 > [ 343.318549] RBP: ffff88800bcd7458 R08: 0000000000000000 R09: > ffffffff94fb8445 > [ 343.319503] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12: > 0000000000000000 > [ 343.320455] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15: > 0000000000000020 > [ 343.321414] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000) > knlGS:0000000000000000 > [ 343.322489] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > [ 343.323283] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4: > 00000000000006e0 > [ 343.324264] Kernel panic - not syncing: Fatal exception in interrupt > [ 343.333717] Dumping ftrace buffer: > [ 343.334175] (ftrace buffer empty) > [ 343.334653] Kernel Offset: 0x13600000 from 0xffffffff81000000 > (relocation range: 0xffffffff80000000-0xffffffffbfffffff) > [ 343.336027] Rebooting in 86400 seconds.. > > [...] Here is the summary with links: - [v4] net: netlink: af_netlink: Prevent empty skb by adding a check on len. https://git.kernel.org/netdev/net/c/f123cffdd8fe You are awesome, thank you! -- Deet-doot-dot, I am a bot. https://korg.docs.kernel.org/patchwork/pwbot.html