CVE-2024-47744 — KVM: Use dedicated mutex to protect kvm_usage_count to avoid deadlock

Affected: Linux

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

KVM: Use dedicated mutex to protect kvm_usage_count to avoid deadlock

Use a dedicated mutex to guard kvm_usage_count to fix a potential deadlock on x86 due to a chain of locks and SRCU synchronizations. Translating the below lockdep splat, CPU1 #6 will wait on CPU0 #1, CPU0 #8 will wait on CPU2 #3, and CPU2 #7 will wait on CPU1 #4 (if there's a writer, due to the fairness of r/w semaphores).

CPU0 CPU1 CPU2 1 lock(&kvm->slots_lock); 2 lock(&vcpu->mutex); 3 lock(&kvm->srcu); 4 lock(cpu_hotplug_lock); 5 lock(kvm_lock); 6 lock(&kvm->slots_lock); 7 lock(cpu_hotplug_lock); 8 sync(&kvm->srcu);

Note, there are likely more potential deadlocks in KVM x86, e.g. the same pattern of taking cpu_hotplug_lock outside of kvm_lock likely exists with __kvmclock_cpufreq_notifier():

USN-7276-1 — linux, linux-lowlatency vulnerabilities

Affected: Ubuntu:24.10: linux, Ubuntu:24.10: linux-lowlatency

Attila Szász discovered that the HFS+ file system implementation in the Linux Kernel contained a heap overflow vulnerability. An attacker could use a specially crafted file system image that, when mounted, could cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2025-0927)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - ARM32 architecture; - ARM64 architecture; - PowerPC architecture; - RISC-V architecture; - S390 architecture; - SuperH RISC architecture; - User-Mode Linux (UML); - x86 architecture; - Block layer subsystem; - Cryptographic API; - Compute Acceleration Framework; - ACPI drivers; - Drivers core; - ATA over ethernet (AOE) driver; - RAM backed block device driver; - Network block device driver; - Ublk userspace block driver; - Compressed RAM block device driver; - Bluetooth drivers; - TPM device driver; - Clock framework and drivers; - Data acquisition framework and drivers; - CPU frequency scaling framework; - Hardware crypto device drivers; - CXL (Compute Express Link) drivers; - DAX dirext access to differentiated memory framework; - Buffer Sharing and Synchronization framework; - EDAC drivers; - FireWire subsystem; - ARM SCMI message protocol; - ARM SCPI message protocol; - EFI core; - Qualcomm firmware drivers; - GPIO subsystem;…

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CVE-2024-47744 — KVM: Use dedicated mutex to protect kvm_usage_count to avoid deadlock

USN-7276-1 — linux, linux-lowlatency vulnerabilities