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Thu, 26 Mar 2020 11:38:46 -0400 Received: from mail-vs1-f67.google.com ([209.85.217.67]:39183 "EHLO mail-vs1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727612AbgCZPip (ORCPT ); Thu, 26 Mar 2020 11:38:45 -0400 Received: by mail-vs1-f67.google.com with SMTP id j128so4115779vsd.6; Thu, 26 Mar 2020 08:38:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=HvMnncn1TWI1BUA76/imMhrXXc8pw/VrjlqspT0N78w=; b=D+6LFS+Zf421ZeDTXPAV8XjVrApEykCv115uEY7z4mgvXJZkSfeb/tRNFie/Yo2zYy O+gqEE1+JiB7/8NTnLZ1KdTUdGWdCQz49gmszFXMAlx+rKi5NKZaFOkJHT+W3mOgxPvG RZsrz1lYDHeEuGkaaT5XiXzLDQUpiYyhYf8PvFDD1R7TlSBKytrIh8EjAen8j94k97Ll JZkXWAc4wqx0RzomgiFTnkk1LSB4dhWrNGao2Sk4Rvmr2U0PF0edCI3jA8UBQhGgKGKo zzsWN9umz5+Ew7y5JjjUoqUjwqI2Y+8BznpIQUWq99veNWqwAN14AfYrD2NxOMUWn9Dl u8ug== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=HvMnncn1TWI1BUA76/imMhrXXc8pw/VrjlqspT0N78w=; b=tCQ/4dPzXvhNN7OP0n/LDVa34Q/t6KaK7LqE39xeHP6dT8CAILracWPl7R8D1ttwZ0 +VlK+vuTxF3kOL8PdTtfRYeUaU6nUg6rbqau0lDf7zDff+LA9+ya9h1nKDrsryQFv33T gEJeBxC/8RqfZvGprAAj7URCQEJM0Tz6UDF8V+MbRdNYrszUTSapeQNB/wZvP9o0/LtD HZV18l/+UKkxMgqmo8L0yujq1CKoaX5MilZKQeoAx4iTes1SA44MVwPJlARB3JWLVwZN vvD1WRnKcgryATdKJinYliSoa+pRno1YMw7EeFx4KzBZthN3EIK7rpHnM0j4U0RLvZS2 0iSw== X-Gm-Message-State: ANhLgQ0HAQTWSQbfC2sZZ2K9qfTTHOXZYDeIu5WDvukg+6nthUt4xIVR C6F3pgEo/XoCb8Dq8fmKvbrZBXQkQl5GwW0swFs= X-Google-Smtp-Source: ADFU+vsfXmR2Mp3IYPyqU7Uqk4xBGVGG7+PwXLTwdGsctT/9BmD13neKqizcXgT5s4AxpZKa8tum8JMuoMMXbKH0Zp4= X-Received: by 2002:a05:6102:a01:: with SMTP id t1mr7272108vsa.108.1585237123616; Thu, 26 Mar 2020 08:38:43 -0700 (PDT) MIME-Version: 1.0 References: <00000000000088452f05a07621d2@google.com> In-Reply-To: <00000000000088452f05a07621d2@google.com> From: Qiujun Huang Date: Thu, 26 Mar 2020 23:38:32 +0800 Message-ID: Subject: Re: WARNING: refcount bug in sctp_wfree To: syzbot Cc: davem@davemloft.net, kuba@kernel.org, LKML , linux-sctp@vger.kernel.org, marcelo.leitner@gmail.com, netdev@vger.kernel.org, nhorman@tuxdriver.com, syzkaller-bugs , vyasevich@gmail.com Content-Type: multipart/mixed; boundary="000000000000a383e705a1c3c7b6" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --000000000000a383e705a1c3c7b6 Content-Type: text/plain; charset="UTF-8" #syz test: upstream On Tue, Mar 10, 2020 at 9:36 AM syzbot wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 2c523b34 Linux 5.6-rc5 > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=155a5f29e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a5295e161cd85b82 > dashboard link: https://syzkaller.appspot.com/bug?extid=cea71eec5d6de256d54d > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=164b5181e00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=166dd70de00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+cea71eec5d6de256d54d@syzkaller.appspotmail.com > > ------------[ cut here ]------------ > refcount_t: underflow; use-after-free. > WARNING: CPU: 1 PID: 8668 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 > Kernel panic - not syncing: panic_on_warn set ... > CPU: 1 PID: 8668 Comm: syz-executor779 Not tainted 5.6.0-rc5-syzkaller #0 > 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+0x1e9/0x30e lib/dump_stack.c:118 > panic+0x264/0x7a0 kernel/panic.c:221 > __warn+0x209/0x210 kernel/panic.c:582 > report_bug+0x1ac/0x2d0 lib/bug.c:195 > fixup_bug arch/x86/kernel/traps.c:174 [inline] > do_error_trap+0xca/0x1c0 arch/x86/kernel/traps.c:267 > do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286 > invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 > RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 > Code: c7 e4 ff d0 88 31 c0 e8 23 20 b3 fd 0f 0b eb 85 e8 8a 4a e0 fd c6 05 ff 70 b1 05 01 48 c7 c7 10 00 d1 88 31 c0 e8 05 20 b3 fd <0f> 0b e9 64 ff ff ff e8 69 4a e0 fd c6 05 df 70 b1 05 01 48 c7 c7 > RSP: 0018:ffffc90001f577d0 EFLAGS: 00010246 > RAX: 8c9c9070bbb4e500 RBX: 0000000000000003 RCX: ffff8880938a63c0 > RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 > RBP: 0000000000000003 R08: ffffffff815e16e6 R09: fffffbfff15db92a > R10: fffffbfff15db92a R11: 0000000000000000 R12: dffffc0000000000 > R13: ffff88809de82000 R14: ffff8880a89237c0 R15: 1ffff11013be52b0 > sctp_wfree+0x3b1/0x710 net/sctp/socket.c:9111 > skb_release_head_state+0xfb/0x210 net/core/skbuff.c:651 > skb_release_all net/core/skbuff.c:662 [inline] > __kfree_skb+0x22/0x1c0 net/core/skbuff.c:678 > sctp_chunk_destroy net/sctp/sm_make_chunk.c:1454 [inline] > sctp_chunk_put+0x17b/0x200 net/sctp/sm_make_chunk.c:1481 > __sctp_outq_teardown+0x80a/0x9d0 net/sctp/outqueue.c:257 > sctp_association_free+0x21e/0x7c0 net/sctp/associola.c:339 > sctp_cmd_delete_tcb net/sctp/sm_sideeffect.c:930 [inline] > sctp_cmd_interpreter net/sctp/sm_sideeffect.c:1318 [inline] > sctp_side_effects net/sctp/sm_sideeffect.c:1185 [inline] > sctp_do_sm+0x3c01/0x5560 net/sctp/sm_sideeffect.c:1156 > sctp_primitive_ABORT+0x93/0xc0 net/sctp/primitive.c:104 > sctp_close+0x231/0x770 net/sctp/socket.c:1512 > inet_release+0x135/0x180 net/ipv4/af_inet.c:427 > __sock_release net/socket.c:605 [inline] > sock_close+0xd8/0x260 net/socket.c:1283 > __fput+0x2d8/0x730 fs/file_table.c:280 > task_work_run+0x176/0x1b0 kernel/task_work.c:113 > exit_task_work include/linux/task_work.h:22 [inline] > do_exit+0x5ef/0x1f80 kernel/exit.c:801 > do_group_exit+0x15e/0x2c0 kernel/exit.c:899 > __do_sys_exit_group+0x13/0x20 kernel/exit.c:910 > __se_sys_exit_group+0x10/0x10 kernel/exit.c:908 > __x64_sys_exit_group+0x37/0x40 kernel/exit.c:908 > do_syscall_64+0xf3/0x1b0 arch/x86/entry/common.c:294 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > RIP: 0033:0x43ef98 > Code: Bad RIP value. > RSP: 002b:00007ffcc7e7c398 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000043ef98 > RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 > RBP: 00000000004be7a8 R08: 00000000000000e7 R09: ffffffffffffffd0 > R10: 000000002059aff8 R11: 0000000000000246 R12: 0000000000000001 > R13: 00000000006d01a0 R14: 0000000000000000 R15: 0000000000000000 > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches --000000000000a383e705a1c3c7b6 Content-Type: application/octet-stream; name="0001-sctp-fix-refcount-bug-in-sctp_wfree.patch" Content-Disposition: attachment; filename="0001-sctp-fix-refcount-bug-in-sctp_wfree.patch" Content-Transfer-Encoding: base64 Content-ID: X-Attachment-Id: f_k88x8d1v0 RnJvbSA2NWY2MDBlODVhOGRjNmU2YmNiYWI2OWU0MTExZTgzMDQxZjIyYzMyIE1vbiBTZXAgMTcg MDA6MDA6MDAgMjAwMQpGcm9tOiBRaXVqdW4gSHVhbmcgPGhxamFnYWluQGdtYWlsLmNvbT4KRGF0 ZTogVGh1LCAyNiBNYXIgMjAyMCAyMzoyMjozOCArMDgwMApTdWJqZWN0OiBbUEFUQ0hdIHNjdHA6 IGZpeCByZWZjb3VudCBidWcgaW4gc2N0cF93ZnJlZQoKV2Ugc2hvdWxkIGl0ZXJhdGUgb3ZlciB0 aGUgZGF0YW1zZ3MgdG8gbW9kaWZ5CmFsbCBjaHVua3Moc2ticykgdG8gbmV3c2suCgpUaGUgZm9s bG93aW5nIGNhc2UgY2F1c2UgdGhlIGJ1ZzoKZm9yIHRoZSB0cm91YmxlIFNLQiwgaXQgd2FzIGlu IG91dHEtPnRyYW5zbWl0dGVkIGxpc3QKCnNjdHBfb3V0cV9zYWNrCiAgICAgICAgc2N0cF9jaGVj 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