Affected: Linux

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

KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region()

Do the cache flush of converted pages in svm_register_enc_region() before dropping kvm->lock to fix use-after-free issues where region and/or its array of pages could be freed by a different task, e.g. if userspace has __unregister_enc_region_locked() already queued up for the region.

Note, the "obvious" alternative of using local variables doesn't fully resolve the bug, as region->pages is also dynamically allocated. I.e. the region structure itself would be fine, but region->pages could be freed.

Flushing multiple pages under kvm->lock is unfortunate, but the entire flow is a rare slow path, and the manual flush is only needed on CPUs that lack coherency for encrypted memory.

Affected: Ubuntu:20.04:LTS: linux-gkeop-5.15, Ubuntu:20.04:LTS: linux-intel-iotg-5.15, Ubuntu:22.04:LTS: linux, Ubuntu:22.04:LTS: linux-gcp, Ubuntu:22.04:LTS: linux-gke, Ubuntu:22.04:LTS: linux-gkeop, Ubuntu:22.04:LTS: linux-ibm, Ubuntu:22.04:LTS: linux-intel-iotg, Ubuntu:22.04:LTS: linux-kvm, Ubuntu:22.04:LTS: linux-nvidia and 1 more

Ziming Zhang discovered that the DRM driver for VMware Virtual GPU did not properly handle certain error conditions, leading to a NULL pointer dereference. A local attacker could possibly trigger this vulnerability to cause a denial of service. (CVE-2022-38096)

Gui-Dong Han discovered that the software RAID driver in the Linux kernel contained a race condition, leading to an integer overflow vulnerability. A privileged attacker could possibly use this to cause a denial of service (system crash). (CVE-2024-23307)

It was discovered that a race condition existed in the Bluetooth subsystem in the Linux kernel when modifying certain settings values through debugfs. A privileged local attacker could use this to cause a denial of service. (CVE-2024-24857, CVE-2024-24858, CVE-2024-24859)

Bai Jiaju discovered that the Xceive XC4000 silicon tuner device driver in the Linux kernel contained a race condition, leading to an integer overflow vulnerability. An attacker could possibly use this to cause a denial of service (system crash). (CVE-2024-24861)

Chenyuan Yang discovered that the Unsorted Block Images (UBI) flash device volume management subsystem did not properly validate logical eraseblock sizes in certain situations. An attacker could possibly use this to cause a denial of service (system crash). (CVE-2024-25739)

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 follow…