In the Linux kernel, the following vulnerability has been resolved:

KVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2()

Add SRCU read-side protection when reading PDPTR registers in
__get_sregs2().

Reading PDPTRs may trigger access to guest memory:
kvm_pdptr_read() -> svm_cache_reg() -> load_pdptrs() ->
kvm_vcpu_read_guest_page() -> kvm_vcpu_gfn_to_memslot()

kvm_vcpu_gfn_to_memslot() dereferences memslots via __kvm_memslots(),
which uses srcu_dereference_check() and requires either kvm->srcu or
kvm->slots_lock to be held. Currently only vcpu->mutex is held,
triggering lockdep warning:

=============================
WARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot
6.12.59+ #3 Not tainted

include/linux/kvm_host.h:1062 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.5.1717/15100:
#0: ff1100002f4b00b0 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d5/0x1590

Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xf0/0x120 lib/dump_stack.c:120
lockdep_rcu_suspicious+0x1e3/0x270 kernel/locking/lockdep.c:6824
__kvm_memslots include/linux/kvm_host.h:1062 [inline]
__kvm_memslots include/linux/kvm_host.h:1059 [inline]
kvm_vcpu_memslots include/linux/kvm_host.h:1076 [inline]
kvm_vcpu_gfn_to_memslot+0x518/0x5e0 virt/kvm/kvm_main.c:2617
kvm_vcpu_read_guest_page+0x27/0x50 virt/kvm/kvm_main.c:3302
load_pdptrs+0xff/0x4b0 arch/x86/kvm/x86.c:1065
svm_cache_reg+0x1c9/0x230 arch/x86/kvm/svm/svm.c:1688
kvm_pdptr_read arch/x86/kvm/kvm_cache_regs.h:141 [inline]
__get_sregs2 arch/x86/kvm/x86.c:11784 [inline]
kvm_arch_vcpu_ioctl+0x3e20/0x4aa0 arch/x86/kvm/x86.c:6279
kvm_vcpu_ioctl+0x856/0x1590 virt/kvm/kvm_main.c:4663
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xbd/0x1d0 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

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No workaround given by the vendor.

History

Thu, 07 May 2026 04:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-362

Thu, 07 May 2026 00:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-820
References
Metrics threat_severity

None

cvssV3_1

{'score': 7.0, 'vector': 'CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H'}

threat_severity

Moderate


Wed, 06 May 2026 16:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-362

Wed, 06 May 2026 12:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2() Add SRCU read-side protection when reading PDPTR registers in __get_sregs2(). Reading PDPTRs may trigger access to guest memory: kvm_pdptr_read() -> svm_cache_reg() -> load_pdptrs() -> kvm_vcpu_read_guest_page() -> kvm_vcpu_gfn_to_memslot() kvm_vcpu_gfn_to_memslot() dereferences memslots via __kvm_memslots(), which uses srcu_dereference_check() and requires either kvm->srcu or kvm->slots_lock to be held. Currently only vcpu->mutex is held, triggering lockdep warning: ============================= WARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot 6.12.59+ #3 Not tainted include/linux/kvm_host.h:1062 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.5.1717/15100: #0: ff1100002f4b00b0 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d5/0x1590 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xf0/0x120 lib/dump_stack.c:120 lockdep_rcu_suspicious+0x1e3/0x270 kernel/locking/lockdep.c:6824 __kvm_memslots include/linux/kvm_host.h:1062 [inline] __kvm_memslots include/linux/kvm_host.h:1059 [inline] kvm_vcpu_memslots include/linux/kvm_host.h:1076 [inline] kvm_vcpu_gfn_to_memslot+0x518/0x5e0 virt/kvm/kvm_main.c:2617 kvm_vcpu_read_guest_page+0x27/0x50 virt/kvm/kvm_main.c:3302 load_pdptrs+0xff/0x4b0 arch/x86/kvm/x86.c:1065 svm_cache_reg+0x1c9/0x230 arch/x86/kvm/svm/svm.c:1688 kvm_pdptr_read arch/x86/kvm/kvm_cache_regs.h:141 [inline] __get_sregs2 arch/x86/kvm/x86.c:11784 [inline] kvm_arch_vcpu_ioctl+0x3e20/0x4aa0 arch/x86/kvm/x86.c:6279 kvm_vcpu_ioctl+0x856/0x1590 virt/kvm/kvm_main.c:4663 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xbd/0x1d0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Title KVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2()
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-06T11:28:16.766Z

Reserved: 2026-05-01T14:12:55.993Z

Link: CVE-2026-43214

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2026-05-06T12:16:40.920

Modified: 2026-05-06T13:07:51.607

Link: CVE-2026-43214

cve-icon Redhat

Severity : Moderate

Publid Date: 2026-05-06T00:00:00Z

Links: CVE-2026-43214 - Bugzilla

cve-icon OpenCVE Enrichment

Updated: 2026-05-07T06:15:23Z

Weaknesses