From: syzbot <syzbot+75475908cd0910f141ee@syzkaller.appspotmail.com>
To: kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
pbonzini@redhat.com, rkrcmar@redhat.com,
syzkaller-bugs@googlegroups.com
Subject: Re: WARNING: suspicious RCU usage in kvm_dev_ioctl
Date: Sat, 02 Nov 2019 17:27:09 -0700 [thread overview]
Message-ID: <00000000000073b15c05966642c3@google.com> (raw)
In-Reply-To: <000000000000bd85b40596657dfa@google.com>
syzbot has found a reproducer for the following crash on:
HEAD commit: 9d234505 Merge tag 'hwmon-for-v5.4-rc6' of git://git.kerne..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=15bf068ae00000
kernel config: https://syzkaller.appspot.com/x/.config?x=cbbed3e8d4eb64bf
dashboard link: https://syzkaller.appspot.com/bug?extid=75475908cd0910f141ee
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14e20268e00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15209b84e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+75475908cd0910f141ee@syzkaller.appspotmail.com
=============================
WARNING: suspicious RCU usage
5.4.0-rc5+ #0 Not tainted
-----------------------------
include/linux/kvm_host.h:534 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
no locks held by syz-executor978/9604.
stack backtrace:
CPU: 0 PID: 9604 Comm: syz-executor978 Not tainted 5.4.0-rc5+ #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+0x172/0x1f0 lib/dump_stack.c:113
lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5438
kvm_get_bus include/linux/kvm_host.h:534 [inline]
kvm_get_bus include/linux/kvm_host.h:532 [inline]
kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:706 [inline]
kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3444
[inline]
kvm_dev_ioctl+0x100c/0x1610 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3496
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:509 [inline]
do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696
ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
__do_sys_ioctl fs/ioctl.c:720 [inline]
__se_sys_ioctl fs/ioctl.c:718 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441159
Code: e8 fc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 9b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdef5e0888 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441159
RDX: 0000000000000002 RSI: 000000000000ae01 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000401f80
R13: 0000000000402010 R14: 0000000000000000 R15: 0000000000000000
=============================
WARNING: suspicious RCU usage
5.4.0-rc5+ #0 Not tainted
-----------------------------
include/linux/kvm_host.h:629 suspicious rcu_dereference_check() usage!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
no locks held by syz-executor978/9604.
stack backtrace:
CPU: 0 PID: 9604 Comm: syz-executor978 Not tainted 5.4.0-rc5+ #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+0x172/0x1f0 lib/dump_stack.c:113
lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5438
__kvm_memslots include/linux/kvm_host.h:629 [inline]
__kvm_memslots include/linux/kvm_host.h:626 [inline]
kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:708 [inline]
kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:3444
[inline]
kvm_dev_ioctl+0x116c/0x1610 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3496
vfs_ioctl fs/ioctl.c:46 [inline]
file_ioctl fs/ioctl.c:509 [inline]
do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696
ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
__do_sys_ioctl fs/ioctl.c:720 [inline]
__se_sys_ioctl fs/ioctl.c:718 [inline]
__x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441159
Code: e8 fc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 9b 09 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdef5e0888 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000441159
RDX: 0000000000000002 RSI: 000000000000ae01 RDI: 0000000000000003
RBP: 00000000006cb018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000401f80
R13: 0000000000402010 R14: 0000000000000000 R15: 0000000000000000
next prev parent reply other threads:[~2019-11-03 0:27 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-11-02 23:32 WARNING: suspicious RCU usage in kvm_dev_ioctl syzbot
2019-11-03 0:27 ` syzbot [this message]
2019-11-03 4:36 ` syzbot
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