In the Linux kernel, the following vulnerability has been resolved:
KVM: SVM: Skip fastpath emulation on VM-Exit if next RIP isn't valid
Skip the WRMSR and HLT fastpaths in SVM's VM-Exit handler if the next RIP
isn't valid, e.g. because KVM is running with nrips=false. SVM must
decode and emulate to skip the instruction if the CPU doesn't provide the
next RIP, and getting the instruction bytes to decode requires reading
guest memory. Reading guest memory through the emulator can fault, i.e.
can sleep, which is disallowed since the fastpath handlers run with IRQs
disabled.
BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:106
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 32611, name: qemu
preempt_count: 1, expected: 0
INFO: lockdep is turned off.
irq event stamp: 30580
hardirqs last enabled at (30579): [<ffffffffc08b2527>] vcpu_run+0x1787/0x1db0 [kvm]
hardirqs last disabled at (30580): [<ffffffffb4f62e32>] __schedule+0x1e2/0xed0
softirqs last enabled at (30570): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210
softirqs last disabled at (30568): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210
CPU: 298 UID: 0 PID: 32611 Comm: qemu Tainted: G U 6.16.0-smp--e6c618b51cfe-sleep #782 NONE
Tainted: [U]=USER
Hardware name: Google Astoria-Turin/astoria, BIOS 0.20241223.2-0 01/17/2025
Call Trace:
<TASK>
dump_stack_lvl+0x7d/0xb0
__might_resched+0x271/0x290
__might_fault+0x28/0x80
kvm_vcpu_read_guest_page+0x8d/0xc0 [kvm]
kvm_fetch_guest_virt+0x92/0xc0 [kvm]
__do_insn_fetch_bytes+0xf3/0x1e0 [kvm]
x86_decode_insn+0xd1/0x1010 [kvm]
x86_emulate_instruction+0x105/0x810 [kvm]
__svm_skip_emulated_instruction+0xc4/0x140 [kvm_amd]
handle_fastpath_invd+0xc4/0x1a0 [kvm]
vcpu_run+0x11a1/0x1db0 [kvm]
kvm_arch_vcpu_ioctl_run+0x5cc/0x730 [kvm]
kvm_vcpu_ioctl+0x578/0x6a0 [kvm]
__se_sys_ioctl+0x6d/0xb0
do_syscall_64+0x8a/0x2c0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f479d57a94b
</TASK>
Note, this is essentially a reapply of commit 5c30e8101e8d ("KVM: SVM:
Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"), but with
different justification (KVM now grabs SRCU when skipping the instruction
for other reasons).
KVM: SVM: Skip fastpath emulation on VM-Exit if next RIP isn't valid
Skip the WRMSR and HLT fastpaths in SVM's VM-Exit handler if the next RIP
isn't valid, e.g. because KVM is running with nrips=false. SVM must
decode and emulate to skip the instruction if the CPU doesn't provide the
next RIP, and getting the instruction bytes to decode requires reading
guest memory. Reading guest memory through the emulator can fault, i.e.
can sleep, which is disallowed since the fastpath handlers run with IRQs
disabled.
BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:106
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 32611, name: qemu
preempt_count: 1, expected: 0
INFO: lockdep is turned off.
irq event stamp: 30580
hardirqs last enabled at (30579): [<ffffffffc08b2527>] vcpu_run+0x1787/0x1db0 [kvm]
hardirqs last disabled at (30580): [<ffffffffb4f62e32>] __schedule+0x1e2/0xed0
softirqs last enabled at (30570): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210
softirqs last disabled at (30568): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210
CPU: 298 UID: 0 PID: 32611 Comm: qemu Tainted: G U 6.16.0-smp--e6c618b51cfe-sleep #782 NONE
Tainted: [U]=USER
Hardware name: Google Astoria-Turin/astoria, BIOS 0.20241223.2-0 01/17/2025
Call Trace:
<TASK>
dump_stack_lvl+0x7d/0xb0
__might_resched+0x271/0x290
__might_fault+0x28/0x80
kvm_vcpu_read_guest_page+0x8d/0xc0 [kvm]
kvm_fetch_guest_virt+0x92/0xc0 [kvm]
__do_insn_fetch_bytes+0xf3/0x1e0 [kvm]
x86_decode_insn+0xd1/0x1010 [kvm]
x86_emulate_instruction+0x105/0x810 [kvm]
__svm_skip_emulated_instruction+0xc4/0x140 [kvm_amd]
handle_fastpath_invd+0xc4/0x1a0 [kvm]
vcpu_run+0x11a1/0x1db0 [kvm]
kvm_arch_vcpu_ioctl_run+0x5cc/0x730 [kvm]
kvm_vcpu_ioctl+0x578/0x6a0 [kvm]
__se_sys_ioctl+0x6d/0xb0
do_syscall_64+0x8a/0x2c0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f479d57a94b
</TASK>
Note, this is essentially a reapply of commit 5c30e8101e8d ("KVM: SVM:
Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"), but with
different justification (KVM now grabs SRCU when skipping the instruction
for other reasons).
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
No data.
No data.
OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.
| Vendors | Products |
|---|---|
| Linux |
|
Advisories
No advisories yet.
Fixes
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
References
History
Wed, 29 Oct 2025 11:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Wed, 29 Oct 2025 00:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Tue, 28 Oct 2025 12:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Skip fastpath emulation on VM-Exit if next RIP isn't valid Skip the WRMSR and HLT fastpaths in SVM's VM-Exit handler if the next RIP isn't valid, e.g. because KVM is running with nrips=false. SVM must decode and emulate to skip the instruction if the CPU doesn't provide the next RIP, and getting the instruction bytes to decode requires reading guest memory. Reading guest memory through the emulator can fault, i.e. can sleep, which is disallowed since the fastpath handlers run with IRQs disabled. BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:106 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 32611, name: qemu preempt_count: 1, expected: 0 INFO: lockdep is turned off. irq event stamp: 30580 hardirqs last enabled at (30579): [<ffffffffc08b2527>] vcpu_run+0x1787/0x1db0 [kvm] hardirqs last disabled at (30580): [<ffffffffb4f62e32>] __schedule+0x1e2/0xed0 softirqs last enabled at (30570): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210 softirqs last disabled at (30568): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210 CPU: 298 UID: 0 PID: 32611 Comm: qemu Tainted: G U 6.16.0-smp--e6c618b51cfe-sleep #782 NONE Tainted: [U]=USER Hardware name: Google Astoria-Turin/astoria, BIOS 0.20241223.2-0 01/17/2025 Call Trace: <TASK> dump_stack_lvl+0x7d/0xb0 __might_resched+0x271/0x290 __might_fault+0x28/0x80 kvm_vcpu_read_guest_page+0x8d/0xc0 [kvm] kvm_fetch_guest_virt+0x92/0xc0 [kvm] __do_insn_fetch_bytes+0xf3/0x1e0 [kvm] x86_decode_insn+0xd1/0x1010 [kvm] x86_emulate_instruction+0x105/0x810 [kvm] __svm_skip_emulated_instruction+0xc4/0x140 [kvm_amd] handle_fastpath_invd+0xc4/0x1a0 [kvm] vcpu_run+0x11a1/0x1db0 [kvm] kvm_arch_vcpu_ioctl_run+0x5cc/0x730 [kvm] kvm_vcpu_ioctl+0x578/0x6a0 [kvm] __se_sys_ioctl+0x6d/0xb0 do_syscall_64+0x8a/0x2c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f479d57a94b </TASK> Note, this is essentially a reapply of commit 5c30e8101e8d ("KVM: SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"), but with different justification (KVM now grabs SRCU when skipping the instruction for other reasons). | |
| Title | KVM: SVM: Skip fastpath emulation on VM-Exit if next RIP isn't valid | |
| References |
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-10-28T11:48:18.889Z
Reserved: 2025-04-16T07:20:57.153Z
Link: CVE-2025-40038
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-10-28T12:15:37.733
Modified: 2025-10-28T12:15:37.733
Link: CVE-2025-40038
Redhat
OpenCVE Enrichment
Updated: 2025-10-29T10:58:14Z