CVE-2024-26976 — KVM: Always flush async #PF workqueue when vCPU is being destroyed

Affected: Linux, linux_kernel

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

KVM: Always flush async #PF workqueue when vCPU is being destroyed

Always flush the per-vCPU async #PF workqueue when a vCPU is clearing its completion queue, e.g. when a VM and all its vCPUs is being destroyed. KVM must ensure that none of its workqueue callbacks is running when the last reference to the KVM _module_ is put. Gifting a reference to the associated VM prevents the workqueue callback from dereferencing freed vCPU/VM memory, but does not prevent the KVM module from being unloaded before the callback completes.

Drop the misguided VM refcount gifting, as calling kvm_put_kvm() from async_pf_execute() if kvm_put_kvm() flushes the async #PF workqueue will result in deadlock. async_pf_execute() can't return until kvm_put_kvm() finishes, and kvm_put_kvm() can't return until async_pf_execute() finishes:

WARNING: CPU: 8 PID: 251 at virt/kvm/kvm_main.c:1435 kvm_put_kvm+0x2d/0x320 [kvm] Modules linked in: vhost_net vhost vhost_iotlb tap kvm_intel kvm irqbypass CPU: 8 PID: 251 Comm: kworker/8:1 Tainted: G W 6.6.0-rc1-e7af8d17224a-x86/gmem-vm #119 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Workqueue: events async_pf_execute [kvm] RIP: 0010:kvm_put_kvm+0x2d/0x320 [kvm] Call Trace: <TASK> async_pf_execute+0x198/0x260 [kvm] process_one_work+0x145/0x2d0 worker_thread+0x27e/0x3a0 kthread+0xba/0xe0 ret_from_fork+0x2d/0x50 ret_from_fork_asm+0…

USN-6816-1 — linux, linux-ibm, linux-lowlatency, linux-raspi vulnerabilities

Affected: Ubuntu:24.04:LTS: linux, Ubuntu:24.04:LTS: linux-ibm, Ubuntu:24.04:LTS: linux-lowlatency, Ubuntu:24.04:LTS: linux-raspi

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)

Zheng Wang discovered that the Broadcom FullMAC WLAN driver in the Linux kernel contained a race condition during device removal, leading to a use- after-free vulnerability. A physically proximate attacker could possibly use this to cause a denial of service (system crash). (CVE-2023-47233)

It was discovered that the ATA over Ethernet (AoE) driver in the Linux kernel contained a race condition, leading to a use-after-free vulnerability. An attacker could use this to cause a denial of service or possibly execute arbitrary code. (CVE-2023-6270)

It was discovered that the Atheros 802.11ac wireless driver did not properly validate certain data structures, leading to a NULL pointer dereference. An attacker could possibly use this to cause a denial of service. (CVE-2023-7042)

It was discovered that the Intel Data Streaming and Intel Analytics Accelerator drivers in the Linux kernel allowed direct access to the devices for unprivileged users and virtual machines. A local attacker could use this to cause a denial of service. (CVE-2024-21823)

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 possib…

Most recent entries from all

CVE-2024-26976 — KVM: Always flush async #PF workqueue when vCPU is being destroyed

USN-6816-1 — linux, linux-ibm, linux-lowlatency, linux-raspi vulnerabilities