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WARNING: suspicious RCU usage in kvm_vcpu_memslots

Status: upstream: reported C repro on 2023/03/10 11:13
Bug presence: origin:lts-only
[Documentation on labels]
Reported-by: syzbot+a703fc5de924fa2e1ae8@syzkaller.appspotmail.com
First crash: 419d, last: 5d02h
Fix bisection: the issue occurs on the latest tested release (bisect log)
Crash: WARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot (log)
Repro: C syz .config
  
▶ ▼ Bug presence (2)
Date Name Commit Repro Result
2023/05/05 linux-5.15.y (ToT) 8a7f2a5c5aa1 C [report] WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/05/05 upstream (ToT) 78b421b6a7c6 C Didn't crash
▶ ▼ Fix bisection attempts (3)
Created Duration User Patch Repo Result
2023/09/15 12:26 1h55m fix candidate upstream job log (0)
2023/06/18 19:09 34m bisect fix linux-5.15.y job log (0) log
2023/04/29 00:11 34m bisect fix linux-5.15.y job log (0) log

Sample crash report:
L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/hw-vuln/l1tf.html for details.
=============================
WARNING: suspicious RCU usage
5.15.156-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-executor352/3499:
 #0: ffff88801bcb40c8 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d4/0xcf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:3870

stack backtrace:
CPU: 0 PID: 3499 Comm: syz-executor352 Not tainted 5.15.156-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 __kvm_memslots include/linux/kvm_host.h:878 [inline]
 kvm_vcpu_memslots+0x1b7/0x200 include/linux/kvm_host.h:892
 kvm_vcpu_gfn_to_memslot+0x2b/0x390 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2158
 kvm_vcpu_unmap+0x5d/0x80 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2773
 nested_vmx_vmexit+0x1476/0x2b70 arch/x86/kvm/vmx/nested.c:4662
 vmx_leave_nested+0x7d/0xb0 arch/x86/kvm/vmx/nested.c:6322
 kvm_leave_nested arch/x86/kvm/x86.c:618 [inline]
 kvm_vcpu_ioctl_x86_set_vcpu_events+0x8d8/0x10e0 arch/x86/kvm/x86.c:4810
 kvm_arch_vcpu_ioctl+0x120e/0x1d40 arch/x86/kvm/x86.c:5295
 kvm_vcpu_ioctl+0x6db/0xcf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4049
 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+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f7f7510e239
Code: 48 83 c4 28 c3 e8 37 17 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff3ffe0a38 EFLAGS: 00000246 ORIG_RAX: 0000000000000010

Crashes (104):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/04/27 10:23 linux-5.15.y c52b9710c83d 07b455f9 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/01/11 20:14 linux-5.15.y 26c690eff0a5 00f3cc59 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/03/26 04:43 linux-5.15.y 115472395b0a fbf0499a .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/08/29 10:32 linux-5.15.y 5ddfe5cc8716 7ba13a15 .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/05/19 03:19 linux-5.15.y 9d6bde853685 3bb7af1d .config console log report syz C [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/04/27 20:54 linux-5.15.y b925f60c6ee7 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/04/27 17:56 linux-5.15.y b925f60c6ee7 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/04/27 15:52 linux-5.15.y c52b9710c83d 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/04/27 09:41 linux-5.15.y c52b9710c83d 07b455f9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/04/07 02:45 linux-5.15.y 9465fef4ae35 ca620dd8 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/31 06:36 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/30 02:32 linux-5.15.y 9465fef4ae35 6baf5069 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/29 19:35 linux-5.15.y 9465fef4ae35 c52bcb23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/29 12:36 linux-5.15.y 9465fef4ae35 c52bcb23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/29 08:02 linux-5.15.y 9465fef4ae35 c52bcb23 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/27 11:00 linux-5.15.y 9465fef4ae35 454571b6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/25 11:43 linux-5.15.y b95c01af2113 0ea90952 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/22 18:39 linux-5.15.y b95c01af2113 4b6cdce6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/16 13:13 linux-5.15.y b95c01af2113 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/14 23:29 linux-5.15.y 574362648507 d615901c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/14 09:17 linux-5.15.y 574362648507 8d8ee116 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/13 19:40 linux-5.15.y 574362648507 f919f202 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/03/10 20:04 linux-5.15.y 574362648507 6ee49f2e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/02/27 16:20 linux-5.15.y 458ce51d0356 05e69c83 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/02/13 20:43 linux-5.15.y 6139f2a02fe0 e66542d7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/02/10 23:46 linux-5.15.y 6139f2a02fe0 77b23aa1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/01/12 00:41 linux-5.15.y 26c690eff0a5 dda5a988 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2024/01/11 18:56 linux-5.15.y 26c690eff0a5 00f3cc59 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/12/06 18:37 linux-5.15.y 9b91d36ba301 e3299f55 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/12/06 01:38 linux-5.15.y 9b91d36ba301 858d62d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/12/05 23:57 linux-5.15.y 9b91d36ba301 858d62d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/12/05 20:00 linux-5.15.y 9b91d36ba301 858d62d1 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/12/04 14:35 linux-5.15.y 9b91d36ba301 f819d6f7 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/11/12 02:14 linux-5.15.y 80529b4968a8 6d6dbf8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/11/06 16:52 linux-5.15.y 12952a23a5da 78fae24e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/11/05 11:00 linux-5.15.y 12952a23a5da 500bfdc4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/10/12 14:43 linux-5.15.y 02e21884dcf2 1b231e3c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/10/12 11:13 linux-5.15.y 02e21884dcf2 1b231e3c .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/10/11 03:01 linux-5.15.y 02e21884dcf2 83165b57 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/10/10 07:14 linux-5.15.y 1edcec18cfb7 c9be5398 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/10/10 02:27 linux-5.15.y 1edcec18cfb7 c9be5398 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/10/09 15:11 linux-5.15.y 1edcec18cfb7 3c53c7d9 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/10/08 20:28 linux-5.15.y 1edcec18cfb7 5e837c76 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/09/25 12:37 linux-5.15.y b911329317b4 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/09/17 14:04 linux-5.15.y aff03380bda4 0b6a67ac .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/08/28 11:12 linux-5.15.y 5ddfe5cc8716 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/08/26 15:19 linux-5.15.y 5ddfe5cc8716 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/08/26 11:01 linux-5.15.y f6f7927ac664 7ba13a15 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
2023/03/10 11:13 linux-5.15.y abddfcf701a5 5205ef30 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan WARNING: suspicious RCU usage in kvm_vcpu_memslots
* Struck through repros no longer work on HEAD.