CVE-2022-50228

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

KVM: SVM: Don't BUG if userspace injects an interrupt with GIF=0

Don't BUG/WARN on interrupt injection due to GIF being cleared, since it's trivial for userspace to force the situation via KVM_SET_VCPU_EVENTS (even if having at least a WARN there would be correct for KVM internally generated injections).

kernel BUG at arch/x86/kvm/svm/svm.c:3386! invalid opcode: 0000 [#1] SMP CPU: 15 PID: 926 Comm: smm_test Not tainted 5.17.0-rc3+ #264 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:svm_inject_irq+0xab/0xb0 [kvm_amd] Code: <0f> 0b 0f 1f 00 0f 1f 44 00 00 80 3d ac b3 01 00 00 55 48 89 f5 53 RSP: 0018:ffffc90000b37d88 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88810a234ac0 RCX: 0000000000000006 RDX: 0000000000000000 RSI: ffffc90000b37df7 RDI: ffff88810a234ac0 RBP: ffffc90000b37df7 R08: ffff88810a1fa410 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff888109571000 R14: ffff88810a234ac0 R15: 0000000000000000 FS: 0000000001821380(0000) GS:ffff88846fdc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f74fc550008 CR3: 000000010a6fe000 CR4: 0000000000350ea0 Call Trace: <TASK> inject_pending_event+0x2f7/0x4c0 [kvm] kvm_arch_vcpu_ioctl_run+0x791/0x17a0 [kvm] kvm_vcpu_ioctl+0x26d/0x650 [kvm] __x64_sys_ioctl+0x82/0xb0 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x44/0xae </TASK>

This vulnerability is rated with a Moderate impact because triggering the condition requires local privileges to manage virtual machines via the KVM device node, and exploitation leads to a host denial of service without permitting unauthorized code execution or privilege escalation. The issue specifically affects AMD hardware virtualization where userspace processes can issue ioctl requests during specific guest state transitions. Host systems that do not run AMD virtualization or where access to the KVM subsystem is restricted to trusted administrative services are not exposed to this flaw.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.