{"id":"CVE-2024-46830","state":"PUBLISHED","title":"KVM: x86: Acquire kvm->srcu when handling KVM_SET_VCPU_EVENTS","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Acquire kvm->srcu when handling KVM_SET_VCPU_EVENTS\n\nGrab kvm->srcu when processing KVM_SET_VCPU_EVENTS, as KVM will forcibly\nleave nested VMX/SVM if SMM mode is being toggled, and leaving nested VMX\nreads guest memory.\n\nNote, kvm_vcpu_ioctl_x86_set_vcpu_events() can also be called from KVM_RUN\nvia sync_regs(), which already holds SRCU.  I.e. trying to precisely use\nkvm_vcpu_srcu_read_lock() around the problematic SMM code would cause\nproblems.  Acquiring SRCU isn't all that expensive, so for simplicity,\ngrab it unconditionally for KVM_SET_VCPU_EVENTS.\n\n =============================\n WARNING: suspicious RCU usage\n 6.10.0-rc7-332d2c1d713e-next-vm #552 Not tainted\n -----------------------------\n include/linux/kvm_host.h:1027 suspicious rcu_dereference_check() usage!\n\n other info that might help us debug this:\n\n rcu_scheduler_active = 2, debug_locks = 1\n 1 lock held by repro/1071:\n  #0: ffff88811e424430 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x7d/0x970 [kvm]\n\n stack backtrace:\n CPU: 15 PID: 1071 Comm: repro Not tainted 6.10.0-rc7-332d2c1d713e-next-vm #552\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n Call Trace:\n  <TASK>\n  dump_stack_lvl+0x7f/0x90\n  lockdep_rcu_suspicious+0x13f/0x1a0\n  kvm_vcpu_gfn_to_memslot+0x168/0x190 [kvm]\n  kvm_vcpu_read_guest+0x3e/0x90 [kvm]\n  nested_vmx_load_msr+0x6b/0x1d0 [kvm_intel]\n  load_vmcs12_host_state+0x432/0xb40 [kvm_intel]\n  vmx_leave_nested+0x30/0x40 [kvm_intel]\n  kvm_vcpu_ioctl_x86_set_vcpu_events+0x15d/0x2b0 [kvm]\n  kvm_arch_vcpu_ioctl+0x1107/0x1750 [kvm]\n  ? mark_held_locks+0x49/0x70\n  ? kvm_vcpu_ioctl+0x7d/0x970 [kvm]\n  ? kvm_vcpu_ioctl+0x497/0x970 [kvm]\n  kvm_vcpu_ioctl+0x497/0x970 [kvm]\n  ? lock_acquire+0xba/0x2d0\n  ? find_held_lock+0x2b/0x80\n  ? do_user_addr_fault+0x40c/0x6f0\n  ? lock_release+0xb7/0x270\n  __x64_sys_ioctl+0x82/0xb0\n  do_syscall_64+0x6c/0x170\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7ff11eb1b539\n  </TASK>","publishedAt":"2024-09-27T12:39:28.396Z","updatedAt":"2026-08-05T11:38:52.433Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e302786233e6bc512986d007c96458ccf5ca21c7","status":"affected","lessThan":"5f35099fa3d59caf10bda88b033538e90086684e","versionType":"git"},{"version":"f7e570780efc5cec9b2ed1e0472a7da14e864fdb","status":"affected","lessThan":"fa297c33faefe51e10244e8a378837fca4963228","versionType":"git"},{"version":"f7e570780efc5cec9b2ed1e0472a7da14e864fdb","status":"affected","lessThan":"939375737b5a0b1bf9b1e75129054e11bc9ca65e","versionType":"git"},{"version":"f7e570780efc5cec9b2ed1e0472a7da14e864fdb","status":"affected","lessThan":"ecdbe8ac86fb5538ccc623a41f88ec96c7168ab9","versionType":"git"},{"version":"f7e570780efc5cec9b2ed1e0472a7da14e864fdb","status":"affected","lessThan":"4bcdd831d9d01e0fb64faea50732b59b2ee88da1","versionType":"git"},{"version":"080dbe7e9b86a0392d8dffc00d9971792afc121f","status":"affected","versionType":"git"},{"version":"b4c0d89c92e957ecccce12e66b63875d0cc7af7e","status":"affected","versionType":"git"},{"version":"5.15.19","status":"affected","lessThan":"5.15.198","versionType":"semver"},{"version":"5.10.97","status":"affected","lessThan":"5.11","versionType":"semver"},{"version":"5.16.5","status":"affected","lessThan":"5.17","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/kvm/x86.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"5.15.198","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.110","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.51","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.10","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/kvm/x86.c"]}],"references":["https://git.kernel.org/stable/c/5f35099fa3d59caf10bda88b033538e90086684e","https://git.kernel.org/stable/c/fa297c33faefe51e10244e8a378837fca4963228","https://git.kernel.org/stable/c/939375737b5a0b1bf9b1e75129054e11bc9ca65e","https://git.kernel.org/stable/c/ecdbe8ac86fb5538ccc623a41f88ec96c7168ab9","https://git.kernel.org/stable/c/4bcdd831d9d01e0fb64faea50732b59b2ee88da1","https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/46xxx/CVE-2024-46830.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-46830","state":"PUBLISHED","datePublished":"2024-09-27T12:39:28.396Z","dateUpdated":"2026-08-05T11:38:52.433Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-09-11T15:12:18.286Z"},"containers":{"cna":{"title":"KVM: x86: Acquire kvm->srcu when handling KVM_SET_VCPU_EVENTS","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Acquire kvm->srcu when handling KVM_SET_VCPU_EVENTS\n\nGrab kvm->srcu when processing KVM_SET_VCPU_EVENTS, as KVM will forcibly\nleave nested VMX/SVM if SMM mode is being toggled, and leaving nested VMX\nreads guest memory.\n\nNote, kvm_vcpu_ioctl_x86_set_vcpu_events() can also be called from KVM_RUN\nvia sync_regs(), which already holds SRCU.  I.e. trying to precisely use\nkvm_vcpu_srcu_read_lock() around the problematic SMM code would cause\nproblems.  Acquiring SRCU isn't all that expensive, so for simplicity,\ngrab it unconditionally for KVM_SET_VCPU_EVENTS.\n\n =============================\n WARNING: suspicious RCU usage\n 6.10.0-rc7-332d2c1d713e-next-vm #552 Not tainted\n -----------------------------\n include/linux/kvm_host.h:1027 suspicious rcu_dereference_check() usage!\n\n other info that might help us debug this:\n\n rcu_scheduler_active = 2, debug_locks = 1\n 1 lock held by repro/1071:\n  #0: ffff88811e424430 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x7d/0x970 [kvm]\n\n stack backtrace:\n CPU: 15 PID: 1071 Comm: repro Not tainted 6.10.0-rc7-332d2c1d713e-next-vm #552\n Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015\n Call Trace:\n  <TASK>\n  dump_stack_lvl+0x7f/0x90\n  lockdep_rcu_suspicious+0x13f/0x1a0\n  kvm_vcpu_gfn_to_memslot+0x168/0x190 [kvm]\n  kvm_vcpu_read_guest+0x3e/0x90 [kvm]\n  nested_vmx_load_msr+0x6b/0x1d0 [kvm_intel]\n  load_vmcs12_host_state+0x432/0xb40 [kvm_intel]\n  vmx_leave_nested+0x30/0x40 [kvm_intel]\n  kvm_vcpu_ioctl_x86_set_vcpu_events+0x15d/0x2b0 [kvm]\n  kvm_arch_vcpu_ioctl+0x1107/0x1750 [kvm]\n  ? mark_held_locks+0x49/0x70\n  ? kvm_vcpu_ioctl+0x7d/0x970 [kvm]\n  ? kvm_vcpu_ioctl+0x497/0x970 [kvm]\n  kvm_vcpu_ioctl+0x497/0x970 [kvm]\n  ? lock_acquire+0xba/0x2d0\n  ? find_held_lock+0x2b/0x80\n  ? do_user_addr_fault+0x40c/0x6f0\n  ? lock_release+0xb7/0x270\n  __x64_sys_ioctl+0x82/0xb0\n  do_syscall_64+0x6c/0x170\n  entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7ff11eb1b539\n  </TASK>"}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"e302786233e6bc512986d007c96458ccf5ca21c7","status":"affected","lessThan":"5f35099fa3d59caf10bda88b033538e90086684e","versionType":"git"},{"version":"f7e570780efc5cec9b2ed1e0472a7da14e864fdb","status":"affected","lessThan":"fa297c33faefe51e10244e8a378837fca4963228","versionType":"git"},{"version":"f7e570780efc5cec9b2ed1e0472a7da14e864fdb","status":"affected","lessThan":"939375737b5a0b1bf9b1e75129054e11bc9ca65e","versionType":"git"},{"version":"f7e570780efc5cec9b2ed1e0472a7da14e864fdb","status":"affected","lessThan":"ecdbe8ac86fb5538ccc623a41f88ec96c7168ab9","versionType":"git"},{"version":"f7e570780efc5cec9b2ed1e0472a7da14e864fdb","status":"affected","lessThan":"4bcdd831d9d01e0fb64faea50732b59b2ee88da1","versionType":"git"},{"version":"080dbe7e9b86a0392d8dffc00d9971792afc121f","status":"affected","versionType":"git"},{"version":"b4c0d89c92e957ecccce12e66b63875d0cc7af7e","status":"affected","versionType":"git"},{"version":"5.15.19","status":"affected","lessThan":"5.15.198","versionType":"semver"},{"version":"5.10.97","status":"affected","lessThan":"5.11","versionType":"semver"},{"version":"5.16.5","status":"affected","lessThan":"5.17","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/kvm/x86.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.17","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.17","versionType":"semver"},{"version":"5.15.198","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.110","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.51","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.10","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/kvm/x86.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/5f35099fa3d59caf10bda88b033538e90086684e"},{"url":"https://git.kernel.org/stable/c/fa297c33faefe51e10244e8a378837fca4963228"},{"url":"https://git.kernel.org/stable/c/939375737b5a0b1bf9b1e75129054e11bc9ca65e"},{"url":"https://git.kernel.org/stable/c/ecdbe8ac86fb5538ccc623a41f88ec96c7168ab9"},{"url":"https://git.kernel.org/stable/c/4bcdd831d9d01e0fb64faea50732b59b2ee88da1"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerability is reached solely through ioctls on a KVM vCPU file descriptor (`KVM_SET_NESTED_STATE` then `KVM_SET_VCPU_EVENTS`), racing against `KVM_SET_USER_MEMORY_REGION` on the VM fd. This requires local access to /dev/kvm with no network component.\nAC:L - The attacker owns both sides of the race — one thread toggles SMM via KVM_SET_VCPU_EVENTS while another deletes/moves memslots — and the two paths take disjoint locks (vcpu->mutex vs kvm->slots_lock). Because the unprotected read is a __copy_from_user() on the attacker's own guest mapping, userfaultfd/FUSE backing can stall the reader inside the window indefinitely, making the race deterministically winnable.\nPR:L - Only an open /dev/kvm descriptor is needed, which systemd's default udev rule grants world read/write (MODE=0666), and nested-virt CI runners, cloud images, and Android AVF routinely expose KVM to unprivileged users. No CAP_SYS_ADMIN or real root is required.\nUI:N - The attacker's own process performs every step — creating the VM, stuffing nested state, toggling SMM, and cycling memslots. No action by any other user is involved.\nS:U - The attacker is already host userspace and the impact is on the host kernel, so no security boundary is crossed; this is not a guest-to-host escape since guest-initiated SMM transitions go through KVM_RUN, which already holds SRCU. Vulnerable and impacted components share the same security authority.\nC:H - The missing SRCU read lock yields a use-after-free read of a kfree()'d struct kvm_memory_slot and of rbtree nodes in search_memslots(), and a reallocated slot gives the attacker control of userspace_addr/base_gfn/npages plus arch.rmap pointers. This permits reading memory of deleted regions and, via heap grooming, arbitrary kernel-memory disclosure.\nI:H - A freed slot that is reallocated with attacker-groomed contents is used to compute host addresses and is consumed by KVM's MMU and nested_vmx_load_msr(), and the concurrently-mutated rbtree traversal writes back into slots->last_used_slot. This gives the corruption-and-control-flow primitives characteristic of an exploitable heap UAF.\nA:H - Dereferencing freed memslot objects and walking an rbtree whose nodes are being freed under the reader reliably produces wild-pointer dereferences, oopses, and kernel panics. Any local user with /dev/kvm can trigger this in a loop to crash the host."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:38:52.433Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.19","versionEndExcluding":"5.15.198"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.1.110"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.6.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.10.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.17","versionEndExcluding":"6.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.16.5"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-09-29T14:12:09.375859Z","id":"CVE-2024-46830","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-29T14:12:18.179Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T22:19:21.236Z"}}]}}}