On May 10, 2019 3:07:05 AM GMT+02:00, syzbot <[email protected]> wrote: >Hello, > >syzbot found the following crash on: > >HEAD commit: a2d635de Merge tag 'drm-next-2019-05-09' of >git://anongit... >git tree: upstream >console output: >https://syzkaller.appspot.com/x/log.txt?x=12b36dd0a00000 >kernel config: >https://syzkaller.appspot.com/x/.config?x=2ef407aed78c3758 >dashboard link: >https://syzkaller.appspot.com/bug?extid=3286e58549edc479faae >compiler: gcc (GCC) 9.0.0 20181231 (experimental) >userspace arch: i386 >syz repro: >https://syzkaller.appspot.com/x/repro.syz?x=12d85ec8a00000 >C reproducer: >https://syzkaller.appspot.com/x/repro.c?x=11df8778a00000 > >The bug was bisected to: > >commit b3e5838252665ee4cfa76b82bdf1198dca81e5be >Author: Christian Brauner <[email protected]> >Date: Wed Mar 27 12:04:15 2019 +0000 > > clone: add CLONE_PIDFD > >bisection log: >https://syzkaller.appspot.com/x/bisect.txt?x=14fe77b4a00000 >final crash: >https://syzkaller.appspot.com/x/report.txt?x=16fe77b4a00000 >console output: >https://syzkaller.appspot.com/x/log.txt?x=12fe77b4a00000 > >IMPORTANT: if you fix the bug, please add the following tag to the >commit: >Reported-by: [email protected] >Fixes: b3e583825266 ("clone: add CLONE_PIDFD") > > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 >RIP: 0023:0xf7fec849 >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:00000000ffed5a8c EFLAGS: 00000246 ORIG_RAX: 0000000000000078 >RAX: ffffffffffffffda RBX: 0000000000003ffc RCX: 0000000000000000 >RDX: 00000000200005c0 RSI: 0000000000000000 RDI: 0000000000000000 >RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000 >R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 >R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 >------------[ cut here ]------------ >DEBUG_LOCKS_WARN_ON(depth <= 0) >WARNING: CPU: 1 PID: 7744 at kernel/locking/lockdep.c:4052 >__lock_release >kernel/locking/lockdep.c:4052 [inline] >WARNING: CPU: 1 PID: 7744 at kernel/locking/lockdep.c:4052 >lock_release+0x667/0xa00 kernel/locking/lockdep.c:4321 >Kernel panic - not syncing: panic_on_warn set ... >CPU: 1 PID: 7744 Comm: syz-executor007 Not tainted 5.1.0+ #4 >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+0x172/0x1f0 lib/dump_stack.c:113 > panic+0x2cb/0x65c kernel/panic.c:214 > __warn.cold+0x20/0x45 kernel/panic.c:566 > report_bug+0x263/0x2b0 lib/bug.c:186 > 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+0x14/0x20 arch/x86/entry/entry_64.S:972 >RIP: 0010:__lock_release kernel/locking/lockdep.c:4052 [inline] >RIP: 0010:lock_release+0x667/0xa00 kernel/locking/lockdep.c:4321 >Code: 0f 85 a0 03 00 00 8b 35 77 66 08 08 85 f6 75 23 48 c7 c6 a0 55 6b >87 >48 c7 c7 40 25 6b 87 4c 89 85 70 ff ff ff e8 b7 a9 eb ff <0f> 0b 4c 8b >85 >70 ff ff ff 4c 89 ea 4c 89 e6 4c 89 c7 e8 52 63 ff >RSP: 0018:ffff888094117b48 EFLAGS: 00010086 >RAX: 0000000000000000 RBX: 1ffff11012822f6f RCX: 0000000000000000 >RDX: 0000000000000000 RSI: ffffffff815af236 RDI: ffffed1012822f5b >RBP: ffff888094117c00 R08: ffff888092bfc400 R09: fffffbfff113301d >R10: fffffbfff113301c R11: ffffffff889980e3 R12: ffffffff8a451df8 >R13: ffffffff8142e71f R14: ffffffff8a44cc80 R15: ffff888094117bd8 > percpu_up_read.constprop.0+0xcb/0x110 include/linux/percpu-rwsem.h:92 > cgroup_threadgroup_change_end include/linux/cgroup-defs.h:712 [inline] > copy_process.part.0+0x47ff/0x6710 kernel/fork.c:2222 > copy_process kernel/fork.c:1772 [inline] > _do_fork+0x25d/0xfd0 kernel/fork.c:2338 > __do_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:240 [inline] > __se_compat_sys_x86_clone arch/x86/ia32/sys_ia32.c:236 [inline] > __ia32_compat_sys_x86_clone+0xbc/0x140 arch/x86/ia32/sys_ia32.c:236 > do_syscall_32_irqs_on arch/x86/entry/common.c:334 [inline] > do_fast_syscall_32+0x281/0xd54 arch/x86/entry/common.c:405 > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 >RIP: 0023:0xf7fec849 >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:00000000ffed5a8c EFLAGS: 00000246 ORIG_RAX: 0000000000000078 >RAX: ffffffffffffffda RBX: 0000000000003ffc RCX: 0000000000000000 >RDX: 00000000200005c0 RSI: 0000000000000000 RDI: 0000000000000000 >RBP: 0000000000000012 R08: 0000000000000000 R09: 0000000000000000 >R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 >R13: 0000000000000000 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 [email protected]. > >syzbot will keep track of this bug report. See: >https://goo.gl/tpsmEJ#status for how to communicate with syzbot. >For information about bisection process see: >https://goo.gl/tpsmEJ#bisection >syzbot can test patches for this bug, for details see: >https://goo.gl/tpsmEJ#testing-patches
I think I know how this comes about. I'll send a patch later today. Christian
