CVE-2026-43214: KVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2()
In the Linux kernel, the following vulnerability has been resolved:
KVM: x86: Add SRCU protection for reading PDPTRs in getsregs2()
Add SRCU read-side protection when reading PDPTR registers in getsregs2().
Reading PDPTRs may trigger access to guest memory: kvmpdptrread() -> svmcachereg() -> loadpdptrs() -> kvmvcpureadguestpage() -> kvmvcpugfntomemslot()
kvmvcpugfntomemslot() dereferences memslots via kvmmemslots(), which uses srcudereferencecheck() and requires either kvm->srcu or kvm->slotslock to be held. Currently only vcpu->mutex is held, triggering lockdep warning:
============================= WARNING: suspicious RCU usage in kvmvcpugfntomemslot 6.12.59+ #3 Not tainted
include/linux/kvmhost.h:1062 suspicious rcudereferencecheck() usage!
other info that might help us debug this:
rcuscheduleractive = 2, debuglocks = 1 1 lock held by syz.5.1717/15100: #0: ff1100002f4b00b0 (&vcpu->mutex){+.+.}-{3:3}, at: kvmvcpuioctl+0x1d5/0x1590
Call Trace: <TASK> dumpstack lib/dumpstack.c:94 [inline] dumpstacklvl+0xf0/0x120 lib/dumpstack.c:120 lockdeprcususpicious+0x1e3/0x270 kernel/locking/lockdep.c:6824 kvmmemslots include/linux/kvmhost.h:1062 [inline] kvmmemslots include/linux/kvmhost.h:1059 [inline] kvmvcpumemslots include/linux/kvmhost.h:1076 [inline] kvmvcpugfntomemslot+0x518/0x5e0 virt/kvm/kvmmain.c:2617 kvmvcpureadguestpage+0x27/0x50 virt/kvm/kvmmain.c:3302 loadpdptrs+0xff/0x4b0 arch/x86/kvm/x86.c:1065 svmcachereg+0x1c9/0x230 arch/x86/kvm/svm/svm.c:1688 kvmpdptrread arch/x86/kvm/kvmcacheregs.h:141 [inline] getsregs2 arch/x86/kvm/x86.c:11784 [inline] kvmarchvcpuioctl+0x3e20/0x4aa0 arch/x86/kvm/x86.c:6279 kvmvcpuioctl+0x856/0x1590 virt/kvm/kvmmain.c:4663 vfsioctl fs/ioctl.c:51 [inline] dosysioctl fs/ioctl.c:907 [inline] sesysioctl fs/ioctl.c:893 [inline] x64sysioctl+0x18b/0x210 fs/ioctl.c:893 dosyscallx64 arch/x86/entry/common.c:52 [inline] dosyscall64+0xbd/0x1d0 arch/x86/entry/common.c:83 entrySYSCALL64afterhwframe+0x77/0x7f
Found by Linux Verification Center (linuxtesting.org) with Syzkaller.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
ubuntu/linux-aws-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1060.63~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1063.71~22.04.1 - Upgrade
Upgrade
ubuntu/linux-azure-fde-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1062.69~22.04.1 - Upgrade
Upgrade
ubuntu/linux-gcp-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1063.69~22.04.1 - Upgrade
Upgrade
ubuntu/linux-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-136.136~22.04.1 - Upgrade
Upgrade
ubuntu/linux-ibm-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1060.61~22.04.1 - Upgrade
Upgrade
ubuntu/linux-lowlatency-hwe-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-134.134.1~22.04.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1058.61~22.04.1 - Upgrade
Upgrade
ubuntu/linux-oracle-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-1057.58~22.04.1 - Upgrade
Upgrade
ubuntu/linux-riscv-6.8to a version that resolves this vulnerability.Fixed in 6.8.0-134.134~22.04.1 - Upgrade
Upgrade
ubuntu/linux-realtime-6.8to a version that resolves this vulnerability.Fixed in 6.8.1-1055.56~22.04.1 - Upgrade
Upgrade
ubuntu/linuxto a version that resolves this vulnerability.Fixed in 6.8.0-134.134 - Upgrade
Upgrade
ubuntu/linux-awsto a version that resolves this vulnerability.Fixed in 6.8.0-1060.63 - Upgrade
Upgrade
ubuntu/linux-azureto a version that resolves this vulnerability.Fixed in 6.8.0-1063.71 - Upgrade
Upgrade
ubuntu/linux-azure-fdeto a version that resolves this vulnerability.Fixed in 6.8.0-1062.69 - Upgrade
Upgrade
ubuntu/linux-azure-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1039.42 - Upgrade
Upgrade
ubuntu/linux-gcpto a version that resolves this vulnerability.Fixed in 6.8.0-1063.69 - Upgrade
Upgrade
ubuntu/linux-gketo a version that resolves this vulnerability.Fixed in 6.8.0-1058.64 - Upgrade
Upgrade
ubuntu/linux-gkeopto a version that resolves this vulnerability.Fixed in 6.8.0-1045.48 - Upgrade
Upgrade
ubuntu/linux-ibmto a version that resolves this vulnerability.Fixed in 6.8.0-1060.61 - Upgrade
Upgrade
ubuntu/linux-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-134.134.1 - Upgrade
Upgrade
ubuntu/linux-nvidiato a version that resolves this vulnerability.Fixed in 6.8.0-1058.61 - Upgrade
Upgrade
ubuntu/linux-nvidia-lowlatencyto a version that resolves this vulnerability.Fixed in 6.8.0-1058.61.1 - Upgrade
Upgrade
ubuntu/linux-nvidia-tegrato a version that resolves this vulnerability.Fixed in 6.8.0-1029.30 - Upgrade
Upgrade
ubuntu/linux-oracleto a version that resolves this vulnerability.Fixed in 6.8.0-1057.58 - Upgrade
Upgrade
ubuntu/linux-raspito a version that resolves this vulnerability.Fixed in 6.8.0-1060.64 - Upgrade
Upgrade
ubuntu/linux-xilinxto a version that resolves this vulnerability.Fixed in 6.8.0-1032.33 - Upgrade
Upgrade
ubuntu/linux-bluefieldto a version that resolves this vulnerability.Fixed in 6.8.0-1026.30 - Upgrade
Upgrade
ubuntu/linux-raspi-realtimeto a version that resolves this vulnerability.Fixed in 6.8.0-2049.50 - Upgrade
Upgrade
ubuntu/linux-realtimeto a version that resolves this vulnerability.Fixed in 6.8.1-1055.56 - Upgrade
Upgrade
ubuntu/linux-aws-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1060.63+fips1 - Upgrade
Upgrade
ubuntu/linux-azure-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1062.69+fips1 - Upgrade
Upgrade
ubuntu/linux-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-134.134+fips1 - Upgrade
Upgrade
ubuntu/linux-gcp-fipsto a version that resolves this vulnerability.Fixed in 6.8.0-1063.69+fips1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.170-1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.12.85-1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.19.6-1 - Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.116-1Fixed in 7.2.15-1Fixed in 7.3.4-1
Event History
Frequently Asked Questions
What is the severity of CVE-2026-43214?
CVE-2026-43214 is considered a moderate severity vulnerability affecting the Linux kernel.
How do I fix CVE-2026-43214?
To resolve CVE-2026-43214, you should update your Linux kernel to a version that includes the security fix.
What versions of the Linux kernel are affected by CVE-2026-43214?
CVE-2026-43214 affects various versions of the Linux kernel between 5.14 to 6.19.
What does CVE-2026-43214 involve?
CVE-2026-43214 involves the addition of SRCU protection for reading PDPTRs in the __get_sregs2() function within the Linux kernel.
Is CVE-2026-43214 exploitable?
Yes, CVE-2026-43214 could potentially be exploited if an attacker gains access to the environment where the affected Linux kernel is running.