syzbot


WARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot

Status: auto-obsoleted due to no activity on 2023/07/08 08:17
Reported-by: syzbot+5e3d3f596596c8fec4c3@syzkaller.appspotmail.com
First crash: 587d, last: 587d

Sample crash report:
=============================
WARNING: suspicious RCU usage
5.15.98-syzkaller #0 Not tainted
-----------------------------
include/linux/kvm_host.h:880 suspicious rcu_dereference_check() usage!

other info that might help us debug this:


rcu_scheduler_active = 2, debug_locks = 1
1 lock held by syz-executor.3/8891:
 #0: ffff88801a8800c8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d4/0xcf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3820

stack backtrace:
CPU: 1 PID: 8891 Comm: syz-executor.3 Not tainted 5.15.98-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 __kvm_memslots include/linux/kvm_host.h:878 [inline]
 kvm_vcpu_memslots include/linux/kvm_host.h:892 [inline]
 kvm_vcpu_gfn_to_memslot+0x4ad/0x570 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2120
 kvm_vcpu_unmap+0x5d/0x80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2735
 nested_vmx_vmexit+0x1451/0x2c10 arch/x86/kvm/vmx/nested.c:4656
 vmx_leave_nested+0x7d/0xb0 arch/x86/kvm/vmx/nested.c:6316
 kvm_leave_nested arch/x86/kvm/x86.c:618 [inline]
 kvm_vcpu_ioctl_x86_set_vcpu_events+0x8d8/0x10e0 arch/x86/kvm/x86.c:4793
 kvm_arch_vcpu_ioctl+0x120e/0x1d40 arch/x86/kvm/x86.c:5278
 kvm_vcpu_ioctl+0x6db/0xcf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3999
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:860
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fc7034030f9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fc701975168 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fc703522f80 RCX: 00007fc7034030f9
RDX: 0000000020000080 RSI: 000000004040aea0 RDI: 0000000000000005
RBP: 00007fc70345eae9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffd829b35bf R14: 00007fc701975300 R15: 0000000000022000
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/03/10 08:17 linux-5.15.y d9b4a0c83a2d 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot
* Struck through repros no longer work on HEAD.