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* [moderation/CI] Re: KVM: Fix+harden against bad uaccess using dying VM
@ 2026-10-28  9:14 syzbot ci
  2026-10-28  9:16 ` Pimyn Girgis
  0 siblings, 1 reply; 4+ messages in thread
From: syzbot ci @ 2026-10-28  9:14 UTC (permalink / raw)
  To: syzkaller-upstream-moderation; +Cc: syzbot

syzbot ci has tested the following series

[v3] KVM: Fix+harden against bad uaccess using dying VM
https://lore.kernel.org/all/20261027221209.1560865-1-seanjc@google.com
* [PATCH v3 01/15] KVM: Reject user accesses to guest memory if current->mm != kvm->mm
* [PATCH v3 02/15] KVM: nVMX: Don't force a full nested VM-Exit when destroying a vCPU
* [PATCH v3 03/15] KVM: PPC: Flush/zap all memslots on kvm_arch_flush_shadow_all()
* [PATCH v3 04/15] KVM: x86: Unmap VMAs for KVM-internal memslots when the memslot is freed
* [PATCH v3 05/15] KVM: Disallow setting memslots when the VM is being destroyed
* [PATCH v3 06/15] KVM: Destroy memslots immediately after mmu_notifiers are unregistered
* [PATCH v3 07/15] KVM: WARN if KVM attempts to do guest-related uaccess with "wrong" process
* [PATCH v3 08/15] KVM: WARN and reject guest-based uaccess if VM is dying
* [PATCH v3 09/15] KVM: Pre-check uaccesses in KVM's APIs to read/write guest memory
* [PATCH v3 10/15] KVM: VMX: Explicility free vmcs01, not the current VMCS, in vCPU free paths
* [PATCH v3 11/15] KVM: nVMX: Don't explicitly VMCLEAR+free() vmcs01's shadow VMCS when freeing vCPU
* [PATCH v3 12/15] KVM: nVMX: Cancel the nested VMX Preemption Timer's hrtimer in free_nested()
* [PATCH v3 13/15] KVM: VMX: Explicitly remove dying vCPUs from the PI wakeup list
* [PATCH v3 14/15] KVM: nVMX: Don't switch to vmcs01 when freeing a vCPU
* [PATCH v3 15/15] KVM: nVMX: Don't load+put the vCPU when freeing nested state for a dying vCPU

and found the following issue:
WARNING in vt_vcpu_pi_remove_from_wakeup_list

Full report is available here:
https://ci.syzbot.org/series/c648fc23-f4c2-4346-93cd-b717ef38b27c

***

WARNING in vt_vcpu_pi_remove_from_wakeup_list

tree:      kvm-next
URL:       https://kernel.googlesource.com/pub/scm/virt/kvm/kvm/
base:      7e60162b16f9da0d2fa83da5c1723b6853a0ac1d
arch:      amd64
compiler:  Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/e4ed6c4f-9b58-4549-9ac6-525add47e472/config
syz repro: https://ci.syzbot.org/findings/320f356a-c5e9-41ff-b8f5-3f0866e300b7/syz_repro

------------[ cut here ]------------
refcount_read(&vcpu->kvm->users_count)
WARNING: arch/x86/kvm/vmx/posted_intr.c:154 at vt_vcpu_pi_remove_from_wakeup_list+0x142/0x1f0 arch/x86/kvm/vmx/posted_intr.c:154, CPU#1: syz.2.19/5870
Modules linked in:
CPU: 1 UID: 0 PID: 5870 Comm: syz.2.19 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:vt_vcpu_pi_remove_from_wakeup_list+0x142/0x1f0 arch/x86/kvm/vmx/posted_intr.c:154
Code: 48 85 db 74 2d e8 ee 1b 64 00 eb 0c e8 e7 1b 64 00 eb 05 e8 e0 1b 64 00 5b 41 5e 41 5f 5d e9 c5 b5 87 0a cc e8 cf 1b 64 00 90 <0f> 0b 90 e9 2b ff ff ff e8 c1 1b 64 00 e8 ac 60 cf ff eb da 44 89
RSP: 0018:ffffc900037cf8c8 EFLAGS: 00010293
RAX: ffffffff816404a1 RBX: ffff88816ada8000 RCX: ffff888110eb0000
RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000000
RBP: 0000000000000003 R08: ffff88810fb01f83 R09: 1ffff11021f603f0
R10: dffffc0000000000 R11: ffffed1021f603f1 R12: dffffc0000000000
R13: 00000000fffffff8 R14: ffff88810fb01f80 R15: dffffc0000000000
FS:  00007f9e487ab6c0(0000) GS:ffff8882a7cbf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f07a7ed4870 CR3: 000000010eea9000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 vmx_vcpu_free+0x28/0x400 arch/x86/kvm/vmx/vmx.c:7517
 kvm_arch_vcpu_destroy+0x154/0x380 arch/x86/kvm/x86.c:9556
 kvm_vm_ioctl_create_vcpu+0x76f/0x9f0 virt/kvm/kvm_main.c:4384
 kvm_vm_ioctl+0x442/0xcb0 virt/kvm/kvm_main.c:5294
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f9e4799f1eb
Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00
RSP: 002b:00007f9e487aaed0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f9e4799f1eb
RDX: 0000000000000003 RSI: 000000000000ae41 RDI: 0000000000000085
RBP: 00007f9e47a36b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000c00000 R11: 0000000000000246 R12: 00000000000004ce
R13: 0000200000c00000 R14: 0000200000001040 R15: 00007ffeb7342be8
 </TASK>


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.

Notes:
- The patch will be applied on top of the tested series (as an
  incremental fix).
- To test a new version of the whole series, please send it directly
  to syzbot@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.

The email will later be sent to:
[jmattson@google.com jthoughton@google.com kvm@vger.kernel.org linux-kernel@vger.kernel.org linuxppc-dev@lists.ozlabs.org maddy@linux.ibm.com mason@kernel.org npiggin@gmail.com pbonzini@redhat.com seanjc@google.com]

If the report looks fine to you, reply with:
#syz upstream

If the report is a false positive, reply with
#syz invalid


^ permalink raw reply	[flat|nested] 4+ messages in thread
* [moderation/CI] Re: KVM: Fix+harden against bad uaccess using dying VM
@ 2026-10-02 19:26 syzbot ci
  2026-10-02 20:27 ` Aleksandr Nogikh
  0 siblings, 1 reply; 4+ messages in thread
From: syzbot ci @ 2026-10-02 19:26 UTC (permalink / raw)
  To: syzkaller-upstream-moderation; +Cc: syzbot

syzbot ci has tested the following series

[v2] KVM: Fix+harden against bad uaccess using dying VM
https://lore.kernel.org/all/20261001202234.3794060-1-seanjc@google.com
* [PATCH v2 01/10] KVM: Reject user accesses to guest memory if current->mm != kvm->mm
* [PATCH v2 02/10] KVM: PPC: Flush/zap all memslots on kvm_arch_flush_shadow_all()
* [PATCH v2 03/10] KVM: x86: Unmap VMAs for KVM-internal memslots when the memslot is freed
* [PATCH v2 04/10] KVM: Disallow setting memslots when the VM is being destroyed
* [PATCH v2 05/10] KVM: Destroy memslots immediately after mmu_notifiers are unregistered
* [PATCH v2 06/10] KVM: WARN if KVM attempts to do guest-related uaccess with "wrong" process
* [PATCH v2 07/10] KVM: WARN and reject guest-based uaccess if VM is dying
* [PATCH v2 08/10] KVM: nVMX: Don't flush shadow VMCS12 to guest memory during vCPU teardown
* [PATCH v2 09/10] KVM: nVMX: Don't try to load eVMCS12 page when the VM is dying
* [PATCH v2 10/10] KVM: Pre-check uaccesses in KVM's APIs to read/write guest memory

and found the following issue:
WARNING in __kvm_read_guest_page

Full report is available here:
https://ci.syzbot.org/series/5f8da53a-c584-4176-abcb-7a29eb02e4c4

***

WARNING in __kvm_read_guest_page

tree:      kvm-next
URL:       https://kernel.googlesource.com/pub/scm/virt/kvm/kvm/
base:      d4b7fb647204f0c81dfeae2d1a708e4d858e0c94
arch:      amd64
compiler:  Debian clang version 22.1.8 (++20260613092233+e80beda6e255-1~exp1~20260613092250.77), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/4d4c10d0-f56c-448f-8782-ad4dab8f46d0/config
syz repro: https://ci.syzbot.org/findings/dc5f6c42-c3ab-41b0-9384-1a15798e4820/syz_repro

------------[ cut here ]------------
!__kvm_can_do_uaccess(kvm)
WARNING: ./include/linux/kvm_host.h:1360 at kvm_can_do_uaccess include/linux/kvm_host.h:1360 [inline], CPU#1: syz.1.18/5858
WARNING: ./include/linux/kvm_host.h:1360 at kvm_is_guest_access_ok virt/kvm/kvm_main.c:3216 [inline], CPU#1: syz.1.18/5858
WARNING: ./include/linux/kvm_host.h:1360 at __kvm_read_guest_page+0x38e/0x440 virt/kvm/kvm_main.c:3226, CPU#1: syz.1.18/5858
Modules linked in:
CPU: 1 UID: 0 PID: 5858 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
RIP: 0010:kvm_can_do_uaccess include/linux/kvm_host.h:1360 [inline]
RIP: 0010:kvm_is_guest_access_ok virt/kvm/kvm_main.c:3216 [inline]
RIP: 0010:__kvm_read_guest_page+0x38e/0x440 virt/kvm/kvm_main.c:3226
Code: f2 ff ff ff 0f 44 d8 31 ff e8 5e a4 89 00 89 d8 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d e9 09 ac a8 0a cc e8 83 9e 89 00 90 <0f> 0b 90 bb f2 ff ff ff eb da e8 73 9e 89 00 90 0f 0b 90 bb f2 ff
RSP: 0018:ffffc90003157778 EFLAGS: 00010293
RAX: ffffffff813e2d22 RBX: 0000000000000000 RCX: ffff888174382580
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 1ffff1102217d82a R08: ffff888110bee183 R09: 1ffff1102217dc30
R10: dffffc0000000000 R11: ffffed102217dc31 R12: ffff888110bee180
R13: ffff888174382b40 R14: 1ffff1102217dc30 R15: 0000000000000000
FS:  000055557c0db500(0000) GS:ffff8882a8cda000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f458dfeb840 CR3: 000000016c9d0000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 kvm_vcpu_read_guest+0x64/0x140 virt/kvm/kvm_main.c:3284
 nested_vmx_load_msr+0x133/0x4d0 arch/x86/kvm/vmx/nested.c:1107
 load_vmcs12_host_state+0x10ca/0x1e20 arch/x86/kvm/vmx/nested.c:4930
 __nested_vmx_vmexit+0x1800/0x2d10 arch/x86/kvm/vmx/nested.c:5206
 nested_vmx_vmexit arch/x86/kvm/vmx/nested.h:46 [inline]
 vmx_leave_nested arch/x86/kvm/vmx/nested.c:6891 [inline]
 nested_vmx_free_vcpu+0x8e/0xd0 arch/x86/kvm/vmx/nested.c:389
 vmx_vcpu_free+0x109/0x3e0 arch/x86/kvm/vmx/vmx.c:7653
 kvm_arch_vcpu_destroy+0x154/0x380 arch/x86/kvm/x86.c:9463
 kvm_vcpu_destroy virt/kvm/kvm_main.c:469 [inline]
 kvm_destroy_vcpus+0x123/0x380 virt/kvm/kvm_main.c:489
 kvm_arch_destroy_vm+0x55/0x120 arch/x86/kvm/x86.c:10014
 kvm_destroy_vm virt/kvm/kvm_main.c:1326 [inline]
 kvm_put_kvm+0x93a/0xc80 virt/kvm/kvm_main.c:1359
 kvm_vm_release+0x43/0x50 virt/kvm/kvm_main.c:1382
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:70 [inline]
 exit_to_user_mode_loop+0x204/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7fec79e159
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fff0d2850c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f7feca27da0 RCX: 00007f7fec79e159
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f7feca27da0 R08: 00007f7feca26038 R09: 0000000000000000
R10: 000000000003fdb8 R11: 0000000000000246 R12: 000000000000ec04
R13: 00007f7feca25fac R14: 000000000000e938 R15: 00007fff0d2851d0
 </TASK>


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
This report is generated by a bot. It may contain errors.
syzbot ci engineers can be reached at syzkaller@googlegroups.com.

To test a fix for this bug, please reply with `#syz test`
(on a separate line) and attach the patch to the email.

Notes:
- The patch will be applied on top of the tested series (as an
  incremental fix).
- To test a new version of the whole series, please send it directly
  to syzbot@lists.linux.dev.
- Arguments like custom git repos and branches are not supported.

The email will later be sent to:
[jmattson@google.com kvm@vger.kernel.org linux-kernel@vger.kernel.org linuxppc-dev@lists.ozlabs.org maddy@linux.ibm.com npiggin@gmail.com pbonzini@redhat.com seanjc@google.com]

If the report looks fine to you, reply with:
#syz upstream

If the report is a false positive, reply with
#syz invalid


^ permalink raw reply	[flat|nested] 4+ messages in thread
end of thread, other threads:[~2026-10-28  9:16 UTC | newest]

Thread overview: 4+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2026-10-28  9:14 [moderation/CI] Re: KVM: Fix+harden against bad uaccess using dying VM syzbot ci
2026-10-28  9:16 ` Pimyn Girgis
  -- strict thread matches above, loose matches on Subject: below --
2026-10-02 19:26 syzbot ci
2026-10-02 20:27 ` Aleksandr Nogikh

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