From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-5.5 required=3.0 tests=FROM_LOCAL_HEX, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING, SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BB73BC43387 for ; Fri, 14 Dec 2018 21:58:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EAED42080F for ; Fri, 14 Dec 2018 21:58:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731408AbeLNV6G (ORCPT ); Fri, 14 Dec 2018 16:58:06 -0500 Received: from mail-it1-f200.google.com ([209.85.166.200]:50908 "EHLO mail-it1-f200.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id 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MIME-Version: 1.0 X-Received: by 2002:a24:4d82:: with SMTP id l124mr4322144itb.9.1544824683666; Fri, 14 Dec 2018 13:58:03 -0800 (PST) Date: Fri, 14 Dec 2018 13:58:03 -0800 In-Reply-To: <000000000000de3c7705746dcbb7@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <00000000000082aab3057d028616@google.com> Subject: Re: KASAN: use-after-free Read in ccid_hc_tx_delete From: syzbot To: davem@davemloft.net, dccp@vger.kernel.org, gerrit@erg.abdn.ac.uk, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org syzbot has found a reproducer for the following crash on: HEAD commit: eb6cf9f8cb9d Merge tag 'arm64-fixes' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11a09b6d400000 kernel config: https://syzkaller.appspot.com/x/.config?x=c8970c89a0efbb23 dashboard link: https://syzkaller.appspot.com/bug?extid=3967c1caf256f4d5aefe compiler: gcc (GCC) 8.0.1 20180413 (experimental) userspace arch: i386 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a4895d400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1271cf05400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+3967c1caf256f4d5aefe@syzkaller.appspotmail.com ================================================================== BUG: KASAN: use-after-free in ccid_hc_tx_delete+0xe0/0x100 net/dccp/ccid.c:188 Read of size 8 at addr ffff8881bdce7980 by task syz-executor384/6286 CPU: 1 PID: 6286 Comm: syz-executor384 Not tainted 4.20.0-rc6+ #276 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 ccid_hc_tx_delete+0xe0/0x100 net/dccp/ccid.c:188 dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53 __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344 dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538 dccp_create_openreq_child+0x47a/0x630 net/dccp/minisocks.c:127 dccp_v6_request_recv_sock+0x278/0x2020 net/dccp/ipv6.c:466 dccp_check_req+0x47d/0x6d0 net/dccp/minisocks.c:196 dccp_v6_rcv+0x874/0x1ce9 net/dccp/ipv6.c:744 ip6_input_finish+0x3fc/0x1aa0 net/ipv6/ip6_input.c:384 NF_HOOK include/linux/netfilter.h:289 [inline] ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:427 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:289 [inline] ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4946 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5056 process_backlog+0x24e/0x7a0 net/core/dev.c:5864 napi_poll net/core/dev.c:6287 [inline] net_rx_action+0x7fa/0x19b0 net/core/dev.c:6353 __do_softirq+0x308/0xb7e kernel/softirq.c:292 do_softirq_own_stack+0x2a/0x40 arch/x86/entry/entry_64.S:1027 do_softirq.part.14+0x126/0x160 kernel/softirq.c:337 do_softirq kernel/softirq.c:329 [inline] __local_bh_enable_ip+0x21d/0x260 kernel/softirq.c:189 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:696 [inline] ip6_finish_output2+0xcef/0x2940 net/ipv6/ip6_output.c:121 ip6_finish_output+0x58c/0xc60 net/ipv6/ip6_output.c:154 NF_HOOK_COND include/linux/netfilter.h:278 [inline] ip6_output+0x232/0x9d0 net/ipv6/ip6_output.c:171 dst_output include/net/dst.h:444 [inline] NF_HOOK include/linux/netfilter.h:289 [inline] ip6_xmit+0xf1c/0x2510 net/ipv6/ip6_output.c:275 inet6_csk_xmit+0x375/0x630 net/ipv6/inet6_connection_sock.c:139 dccp_transmit_skb+0x98c/0x12e0 net/dccp/output.c:142 dccp_send_ack+0x1d9/0x360 net/dccp/output.c:595 dccp_rcv_request_sent_state_process net/dccp/input.c:501 [inline] dccp_rcv_state_process+0x152e/0x1b7e net/dccp/input.c:680 dccp_v6_do_rcv+0x271/0xbf0 net/dccp/ipv6.c:638 sk_backlog_rcv include/net/sock.h:932 [inline] __release_sock+0x12f/0x3a0 net/core/sock.c:2276 release_sock+0xad/0x2c0 net/core/sock.c:2789 inet_wait_for_connect net/ipv4/af_inet.c:588 [inline] __inet_stream_connect+0x641/0x1150 net/ipv4/af_inet.c:680 inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719 __sys_connect+0x37d/0x4c0 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __ia32_sys_connect+0x72/0xb0 net/socket.c:1672 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f22a29 Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 14 24 c3 8b 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:00000000f7edc1fc EFLAGS: 00000293 ORIG_RAX: 000000000000016a RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020419000 RDX: 000000000000001c RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00000000003d0f00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6269: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc+0x12e/0x730 mm/slab.c:3554 ccid_new+0x25b/0x3e0 net/dccp/ccid.c:151 dccp_hdlr_ccid+0x27/0x150 net/dccp/feat.c:44 __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344 dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538 dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline] dccp_rcv_state_process+0x1320/0x1b7e net/dccp/input.c:680 dccp_v6_do_rcv+0x271/0xbf0 net/dccp/ipv6.c:638 sk_backlog_rcv include/net/sock.h:932 [inline] __release_sock+0x12f/0x3a0 net/core/sock.c:2276 release_sock+0xad/0x2c0 net/core/sock.c:2789 inet_wait_for_connect net/ipv4/af_inet.c:588 [inline] __inet_stream_connect+0x641/0x1150 net/ipv4/af_inet.c:680 inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:719 __sys_connect+0x37d/0x4c0 net/socket.c:1664 __do_sys_connect net/socket.c:1675 [inline] __se_sys_connect net/socket.c:1672 [inline] __ia32_sys_connect+0x72/0xb0 net/socket.c:1672 do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 Freed by task 6283: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kmem_cache_free+0x83/0x290 mm/slab.c:3760 ccid_hc_tx_delete+0xc3/0x100 net/dccp/ccid.c:190 dccp_hdlr_ccid+0x7d/0x150 net/dccp/feat.c:53 __dccp_feat_activate+0x188/0x280 net/dccp/feat.c:344 dccp_feat_activate_values+0x3c1/0x80a net/dccp/feat.c:1538 dccp_create_openreq_child+0x47a/0x630 net/dccp/minisocks.c:127 dccp_v6_request_recv_sock+0x278/0x2020 net/dccp/ipv6.c:466 dccp_check_req+0x47d/0x6d0 net/dccp/minisocks.c:196 dccp_v6_rcv+0x874/0x1ce9 net/dccp/ipv6.c:744 ip6_input_finish+0x3fc/0x1aa0 net/ipv6/ip6_input.c:384 NF_HOOK include/linux/netfilter.h:289 [inline] ip6_input+0xe9/0x600 net/ipv6/ip6_input.c:427 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x17a/0x330 net/ipv6/ip6_input.c:76 NF_HOOK include/linux/netfilter.h:289 [inline] ipv6_rcv+0x115/0x640 net/ipv6/ip6_input.c:272 __netif_receive_skb_one_core+0x14d/0x200 net/core/dev.c:4946 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:5056 process_backlog+0x24e/0x7a0 net/core/dev.c:5864 napi_poll net/core/dev.c:6287 [inline] net_rx_action+0x7fa/0x19b0 net/core/dev.c:6353 __do_softirq+0x308/0xb7e kernel/softirq.c:292 The buggy address belongs to the object at ffff8881bdce7980 which belongs to the cache ccid2_hc_tx_sock of size 1240 The buggy address is located 0 bytes inside of 1240-byte region [ffff8881bdce7980, ffff8881bdce7e58) The buggy address belongs to the page: page:ffffea0006f73980 count:1 mapcount:0 mapping:ffff8881c5c76680 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0006f71108 ffffea0006f73908 ffff8881c5c76680 raw: 0000000000000000 ffff8881bdce6380 0000000100000005 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881bdce7880: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc ffff8881bdce7900: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc > ffff8881bdce7980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881bdce7a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881bdce7a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================