From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-f70.google.com ([209.85.166.70]:52402 "EHLO mail-io1-f70.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726980AbfKYJMJ (ORCPT ); Mon, 25 Nov 2019 04:12:09 -0500 Received: by mail-io1-f70.google.com with SMTP id o5so10453544iob.19 for ; Mon, 25 Nov 2019 01:12:09 -0800 (PST) MIME-Version: 1.0 Date: Mon, 25 Nov 2019 01:12:08 -0800 Message-ID: <0000000000007cace40598282858@google.com> Subject: WARNING: refcount bug in smc_release (2) From: syzbot Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes Sender: linux-s390-owner@vger.kernel.org List-ID: To: davem@davemloft.net, kgraul@linux.ibm.com, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, netdev@vger.kernel.org, syzkaller-bugs@googlegroups.com, ubraun@linux.ibm.com Hello, syzbot found the following crash on: HEAD commit: c4f2cbd3 Merge branch '100GbE' of git://git.kernel.org/pub.. git tree: net-next console output: https://syzkaller.appspot.com/x/log.txt?x=172bf5cae00000 kernel config: https://syzkaller.appspot.com/x/.config?x=5ac526dc3578c3d3 dashboard link: https://syzkaller.appspot.com/bug?extid=96d3f9ff6a86d37e44c8 compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+96d3f9ff6a86d37e44c8@syzkaller.appspotmail.com ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 20712 at lib/refcount.c:190 refcount_sub_and_test_checked lib/refcount.c:190 [inline] WARNING: CPU: 0 PID: 20712 at lib/refcount.c:190 refcount_sub_and_test_checked+0x1d0/0x200 lib/refcount.c:180 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 20712 Comm: syz-executor.0 Not tainted 5.4.0-rc8-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+0x197/0x210 lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:221 __warn.cold+0x2f/0x35 kernel/panic.c:582 report_bug+0x289/0x300 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:179 [inline] fixup_bug arch/x86/kernel/traps.c:174 [inline] do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028 RIP: 0010:refcount_sub_and_test_checked lib/refcount.c:190 [inline] RIP: 0010:refcount_sub_and_test_checked+0x1d0/0x200 lib/refcount.c:180 Code: 1d fb 91 7d 06 31 ff 89 de e8 6c f1 2d fe 84 db 75 94 e8 23 f0 2d fe 48 c7 c7 00 d9 e6 87 c6 05 db 91 7d 06 01 e8 b8 22 ff fd <0f> 0b e9 75 ff ff ff e8 04 f0 2d fe e9 6e ff ff ff 48 89 df e8 17 RSP: 0018:ffff88807446fa80 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 000000000000f9af RSI: ffffffff815d2076 RDI: ffffed100e88df42 RBP: ffff88807446fb18 R08: ffff888070648580 R09: ffffed1015d04101 R10: ffffed1015d04100 R11: ffff8880ae820807 R12: 00000000ffffffff R13: 0000000000000001 R14: ffff88807446faf0 R15: 0000000000000000 refcount_dec_and_test_checked+0x1b/0x20 lib/refcount.c:220 sock_put include/net/sock.h:1728 [inline] smc_release+0x236/0x3e0 net/smc/af_smc.c:202 __sock_release+0xce/0x280 net/socket.c:590 sock_close+0x1e/0x30 net/socket.c:1268 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 get_signal+0x2078/0x2500 kernel/signal.c:2528 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x65f/0x760 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x45a639 Code: ad b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f1a52923c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a RAX: ffffffffffffff8d RBX: 0000000000000003 RCX: 000000000045a639 RDX: 0000000000000010 RSI: 0000000020000000 RDI: 0000000000000003 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1a529246d4 R13: 00000000004c0dc8 R14: 00000000004d3a00 R15: 00000000ffffffff 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.