GHSA-5C3F-MCW3-6Q2W
Vulnerability from github – Published: 2026-05-06 12:30 – Updated: 2026-05-08 15:31In 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: __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.
{
"affected": [],
"aliases": [
"CVE-2026-43214"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-05-06T12:16:40Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Add SRCU protection for reading PDPTRs in __get_sregs2()\n\nAdd SRCU read-side protection when reading PDPTR registers in\n__get_sregs2().\n\nReading PDPTRs may trigger access to guest memory:\nkvm_pdptr_read() -\u003e svm_cache_reg() -\u003e load_pdptrs() -\u003e\nkvm_vcpu_read_guest_page() -\u003e kvm_vcpu_gfn_to_memslot()\n\nkvm_vcpu_gfn_to_memslot() dereferences memslots via __kvm_memslots(),\nwhich uses srcu_dereference_check() and requires either kvm-\u003esrcu or\nkvm-\u003eslots_lock to be held. Currently only vcpu-\u003emutex is held,\ntriggering lockdep warning:\n\n=============================\nWARNING: suspicious RCU usage in kvm_vcpu_gfn_to_memslot\n6.12.59+ #3 Not tainted\n\ninclude/linux/kvm_host.h:1062 suspicious rcu_dereference_check() usage!\n\nother info that might help us debug this:\n\nrcu_scheduler_active = 2, debug_locks = 1\n1 lock held by syz.5.1717/15100:\n #0: ff1100002f4b00b0 (\u0026vcpu-\u003emutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x1d5/0x1590\n\nCall Trace:\n \u003cTASK\u003e\n __dump_stack lib/dump_stack.c:94 [inline]\n dump_stack_lvl+0xf0/0x120 lib/dump_stack.c:120\n lockdep_rcu_suspicious+0x1e3/0x270 kernel/locking/lockdep.c:6824\n __kvm_memslots include/linux/kvm_host.h:1062 [inline]\n __kvm_memslots include/linux/kvm_host.h:1059 [inline]\n kvm_vcpu_memslots include/linux/kvm_host.h:1076 [inline]\n kvm_vcpu_gfn_to_memslot+0x518/0x5e0 virt/kvm/kvm_main.c:2617\n kvm_vcpu_read_guest_page+0x27/0x50 virt/kvm/kvm_main.c:3302\n load_pdptrs+0xff/0x4b0 arch/x86/kvm/x86.c:1065\n svm_cache_reg+0x1c9/0x230 arch/x86/kvm/svm/svm.c:1688\n kvm_pdptr_read arch/x86/kvm/kvm_cache_regs.h:141 [inline]\n __get_sregs2 arch/x86/kvm/x86.c:11784 [inline]\n kvm_arch_vcpu_ioctl+0x3e20/0x4aa0 arch/x86/kvm/x86.c:6279\n kvm_vcpu_ioctl+0x856/0x1590 virt/kvm/kvm_main.c:4663\n vfs_ioctl fs/ioctl.c:51 [inline]\n __do_sys_ioctl fs/ioctl.c:907 [inline]\n __se_sys_ioctl fs/ioctl.c:893 [inline]\n __x64_sys_ioctl+0x18b/0x210 fs/ioctl.c:893\n do_syscall_x64 arch/x86/entry/common.c:52 [inline]\n do_syscall_64+0xbd/0x1d0 arch/x86/entry/common.c:83\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\n\nFound by Linux Verification Center (linuxtesting.org) with Syzkaller.",
"id": "GHSA-5c3f-mcw3-6q2w",
"modified": "2026-05-08T15:31:18Z",
"published": "2026-05-06T12:30:33Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43214"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/57536ff0a6bd69a5808d682925202babdb5ddc13"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/708e20c66b2761d878a2bc3c7534e7f814e4dec5"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/95d848dc7e639988dbb385a8cba9b484607cf98c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/9f2bfea51151dfbb24b52f452eb3d5f5fe0e506e"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/b33f8d816950b10e7879cd8ffd7ae4b649ada4db"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/f621ca24f9f489e226e22560761b04884984133b"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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