From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753455AbeDAKfV (ORCPT ); Sun, 1 Apr 2018 06:35:21 -0400 Received: from mail-pg0-f53.google.com ([74.125.83.53]:45765 "EHLO mail-pg0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751130AbeDAKfT (ORCPT ); Sun, 1 Apr 2018 06:35:19 -0400 X-Google-Smtp-Source: AIpwx48mXux9AA8l4qQECuO+ukaKXEih/jJKu7dPnk6C5YZ7sx4ALI+9cJBmAb5ZACLqUDqG1o45WwfDGBdvDVGk/+E= MIME-Version: 1.0 In-Reply-To: <001a113ed5546fb3c00568944220@google.com> References: <001a113ed5546fb3c00568944220@google.com> From: Dmitry Vyukov Date: Sun, 1 Apr 2018 12:34:58 +0200 Message-ID: Subject: Re: WARNING in refcount_sub_and_test (2) To: syzbot Cc: David Miller , Alexey Kuznetsov , LKML , netdev , syzkaller-bugs@googlegroups.com, Hideaki YOSHIFUJI Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 30, 2018 at 12:01 AM, syzbot wrote: > Hello, > > syzbot hit the following crash on bpf-next commit > 22527437e0a0c96ee3153e9d0382942b0fd4f9dd (Thu Mar 29 02:36:15 2018 +0000) > Merge branch 'nfp-bpf-updates' > syzbot dashboard link: > https://syzkaller.appspot.com/bug?extid=c7b0dde061c523bc4b0f > > C reproducer: https://syzkaller.appspot.com/x/repro.c?id=5996614741131264 > syzkaller reproducer: > https://syzkaller.appspot.com/x/repro.syz?id=5947747274326016 > Raw console output: > https://syzkaller.appspot.com/x/log.txt?id=6215237837520896 > Kernel config: > https://syzkaller.appspot.com/x/.config?id=-1280663959502969741 > compiler: gcc (GCC) 7.1.1 20170620 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+c7b0dde061c523bc4b0f@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer for > details. > If you forward the report, please keep this part and the footer. Messed kernel output. #syz dup: WARNING: refcount bug in sk_alloc > R13: 0030656c69662f2e R14: 0000000000000005 R15: 2f30656c69662f2e > ------------[ cut here ]------------ > ------------[ cut here ]------------ > refcount_t: increment on 0; use-after-free. > refcount_t: underflow; use-after-free. > WARNING: CPU: 0 PID: 4450 at lib/refcount.c:187 > refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:187 > WARNING: CPU: 1 PID: 4460 at lib/refcount.c:153 refcount_inc+0x47/0x50 > lib/refcount.c:153 > Kernel panic - not syncing: panic_on_warn set ... > > Modules linked in: > CPU: 0 PID: 4450 Comm: syzkaller428798 Not tainted 4.16.0-rc6+ #40 > CPU: 1 PID: 4460 Comm: syzkaller428798 Not tainted 4.16.0-rc6+ #40 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > Call Trace: > RIP: 0010:refcount_inc+0x47/0x50 lib/refcount.c:153 > __dump_stack lib/dump_stack.c:17 [inline] > dump_stack+0x194/0x24d lib/dump_stack.c:53 > RSP: 0018:ffff8801b534f860 EFLAGS: 00010286 > RAX: dffffc0000000008 RBX: ffff8801b1b8c184 RCX: ffffffff815ba4be > panic+0x1e4/0x41c kernel/panic.c:183 > RDX: 0000000000000000 RSI: 1ffff10036a69ebc RDI: 1ffff10036a69e91 > RBP: ffff8801b534f868 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801b534faf8 > R13: ffff8801b04db513 R14: ffff8801b1b8c180 R15: ffff8801b04db501 > FS: 00000000008e6880(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > __warn+0x1dc/0x200 kernel/panic.c:547 > CR2: 00000000006ea510 CR3: 00000001b106f005 CR4: 00000000001606e0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > report_bug+0x1f4/0x2b0 lib/bug.c:186 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 > Call Trace: > fixup_bug arch/x86/kernel/traps.c:247 [inline] > do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 > get_net include/net/net_namespace.h:204 [inline] > sk_alloc+0x3f9/0x1440 net/core/sock.c:1540 > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 > invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 > RIP: 0010:refcount_sub_and_test+0x167/0x1b0 lib/refcount.c:187 > RSP: 0018:ffff8801b0e87728 EFLAGS: 00010286 > RAX: dffffc0000000008 RBX: 0000000000000000 RCX: ffffffff815ba4be > RDX: 0000000000000000 RSI: 1ffff100361d0e95 RDI: 0000000000000293 > RBP: ffff8801b0e877b8 R08: 0000000000000000 R09: 0000000000000000 > R10: ffff8801b0e87850 R11: 0000000000000000 R12: 1ffff100361d0ee6 > inet_create+0x47c/0xf50 net/ipv4/af_inet.c:320 > R13: 00000000ffffffff R14: 0000000000000001 R15: ffff8801b0816204 > __sock_create+0x4d4/0x850 net/socket.c:1285 > sock_create net/socket.c:1325 [inline] > SYSC_socket net/socket.c:1355 [inline] > SyS_socket+0xeb/0x1d0 net/socket.c:1335 > refcount_dec_and_test+0x1a/0x20 lib/refcount.c:212 > put_net include/net/net_namespace.h:222 [inline] > __sk_destruct+0x560/0x920 net/core/sock.c:1592 > do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 > sk_destruct+0x47/0x80 net/core/sock.c:1601 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > __sk_free+0xf1/0x2b0 net/core/sock.c:1612 > RIP: 0033:0x44ac67 > sk_free+0x2a/0x40 net/core/sock.c:1623 > RSP: 002b:00007ffcd4f45588 EFLAGS: 00000202 > sock_put include/net/sock.h:1660 [inline] > tcp_close+0x967/0x1190 net/ipv4/tcp.c:2321 > ORIG_RAX: 0000000000000029 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000044ac67 > RDX: 0000000000000006 RSI: 0000000000000001 RDI: 0000000000000002 > RBP: 00007ffcd4f456b0 R08: 0000000000000000 R09: 0000000000000001 > R10: 0000000000000006 R11: 0000000000000202 R12: 0000000000000002 > inet_release+0xed/0x1c0 net/ipv4/af_inet.c:427 > R13: 0000000000000002 R14: 000000000000b38f R15: 00007ffcd4f456d8 > sock_release+0x8d/0x1e0 net/socket.c:594 > Code: > be > sock_close+0x16/0x20 net/socket.c:1149 > fe > __fput+0x327/0x7e0 fs/file_table.c:209 > 5b > 5d > c3 > ____fput+0x15/0x20 fs/file_table.c:243 > e8 > task_work_run+0x199/0x270 kernel/task_work.c:113 > 5a > 3c > be > fe > tracehook_notify_resume include/linux/tracehook.h:191 [inline] > exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:166 > 80 > 3d > 91 > prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] > syscall_return_slowpath arch/x86/entry/common.c:265 [inline] > do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292 > f5 > 84 > 05 > 00 75 ea e8 4c 3c be > fe > 48 > c7 > c7 > entry_SYSCALL_64_after_hwframe+0x42/0xb7 > 80 > RIP: 0033:0x406fe0 > 78 > RSP: 002b:00007ffcd4f45588 EFLAGS: 00000246 > e5 > ORIG_RAX: 0000000000000003 > 86 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000406fe0 > c6 > RDX: 00000000000000e0 RSI: 00007ffcd4f45e70 RDI: 0000000000000003 > 05 > RBP: 00007ffcd4f456b0 R08: 00007ffcd4f455b0 R09: 0000000000000001 > 7c > R10: 00007ffcd4f456b0 R11: 0000000000000246 R12: 00000000006de4c0 > R13: 00000000006dde40 R14: 0000000000001380 R15: 00007ffcd4f456d8 > f5 84 05 01 e8 f9 47 8e fe <0f> 0b eb ce 0f 1f 44 00 00 55 48 89 e5 41 57 41 > 56 41 55 41 54 > ---[ end trace 04af8119701e2164 ]--- > Dumping ftrace buffer: > (ftrace buffer empty) > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug is > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > To mark this as a duplicate of another syzbot report, please reply with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new bug > report. > Note: all commands must start from beginning of the line in the email body. > > -- > You received this message because you are subscribed to the Google Groups > "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit > https://groups.google.com/d/msgid/syzkaller-bugs/001a113ed5546fb3c00568944220%40google.com. > For more options, visit https://groups.google.com/d/optout.