CVE-2024-4418

A race condition leading to a stack use-after-free flaw was found in libvirt. Due to a bad assumption in the virNetClientIOEventLoop() method, the data pointer to a stack-allocated virNetClientIOEventData structure ended up being used in the virNetClientIOEventFD callback while the data pointer's stack frame was concurrently being "freed" when returning from virNetClientIOEventLoop(). The 'virtproxyd' daemon can be used to trigger requests. If libvirt is configured with fine-grained access control, this issue, in theory, allows a user to escape their otherwise limited access. This flaw allows a local, unprivileged user to access virtproxyd without authenticating. Remote users would need to authenticate before they could access it.

Libvirt is a C toolkit to interact with the virtualization capabilities of recent versions of Linux (and other OSes). The main package includes the libvirtd server exporting the virtualization support.

Security Fix(es):

A race condition leading to a stack use-after-free flaw was found in libvirt. Due to a bad assumption in the virNetClientIOEventLoop() method, the data pointer to a stack-allocated virNetClientIOEventData structure ended up being used in the virNetClientIOEventFD callback while the data pointer's stack frame was concurrently being "freed" when returning from virNetClientIOEventLoop(). The 'virtproxyd' daemon can be used to trigger requests. If libvirt is configured with fine-grained access control, this issue, in theory, allows a user to escape their otherwise limited access. This flaw allows a local, unprivileged user to access virtproxyd without authenticating. Remote users would need to authenticate before they could access it.(CVE-2024-4418)

Libvirt is a C toolkit to interact with the virtualization capabilities of recent versions of Linux (and other OSes). The main package includes the libvirtd server exporting the virtualization support.

Security Fix(es):

A race condition leading to a stack use-after-free flaw was found in libvirt. Due to a bad assumption in the virNetClientIOEventLoop() method, the data pointer to a stack-allocated virNetClientIOEventData structure ended up being used in the virNetClientIOEventFD callback while the data pointer's stack frame was concurrently being "freed" when returning from virNetClientIOEventLoop(). The 'virtproxyd' daemon can be used to trigger requests. If libvirt is configured with fine-grained access control, this issue, in theory, allows a user to escape their otherwise limited access. This flaw allows a local, unprivileged user to access virtproxyd without authenticating. Remote users would need to authenticate before they could access it.(CVE-2024-4418)

Kernel-based Virtual Machine (KVM) offers a full virtualization solution for Linux on numerous hardware platforms. The virt:rhel module contains packages which provide user-space components used to run virtual machines using KVM. The packages also provide APIs for managing and interacting with the virtualized systems.

Security Fix:

• virt:libvirt: stack use-after-free in virNetClientIOEventLoop (CVE-2024-4418)

Bug fix:

• virsh destroy with --graceful destroyed a paused guest (qemu process paused by SIGSTOP) (JIRA:Rocky Linux-36064)

A race condition leading to a stack use-after-free flaw was found in libvirt. Due to a bad assumption in the virNetClientIOEventLoop() method, the data pointer to a stack-allocated virNetClientIOEventData structure ended up being used in the virNetClientIOEventFD callback while the data pointer's stack frame was concurrently being "freed" when returning from virNetClientIOEventLoop(). The 'virtproxyd' daemon can be used to trigger requests. If libvirt is configured with fine-grained access control, this issue, in theory, allows a user to escape their otherwise limited access. This flaw allows a local, unprivileged user to access virtproxyd without authenticating. Remote users would need to authenticate before they could access it.

Kernel-based Virtual Machine (KVM) offers a full virtualization solution for Linux on numerous hardware platforms. The virt:rhel module contains packages which provide user-space components used to run virtual machines using KVM. The packages also provide APIs for managing and interacting with the virtualized systems.

Security Fix:

• virt:rhel/libvirt: stack use-after-free in virNetClientIOEventLoop (CVE-2024-4418)

Bug fix:

• virsh destroy with --graceful destroyed a paused guest (qemu process paused by SIGSTOP) (JIRA:AlmaLinux-36064)

Kernel-based Virtual Machine (KVM) offers a full virtualization solution forLinux on numerous hardware platforms. The virt:rhel module contains packageswhich provide user-space components used to run virtual machines using KVM.The packages also provide APIs for managing and interacting with the virtualized systems.

Security Fix(es):

• libvirt: stack use-after-free in virNetClientIOEventLoop() (CVE-2024-4418)

For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section.

A race condition leading to a stack use-after-free flaw was found in libvirt. Due to a bad assumption in the virNetClientIOEventLoop() method, the data pointer to a stack-allocated virNetClientIOEventData structure ended up being used in the virNetClientIOEventFD callback while the data pointer's stack frame was concurrently being "freed" when returning from virNetClientIOEventLoop(). The 'virtproxyd' daemon can be used to trigger requests. If libvirt is configured with fine-grained access control, this issue, in theory, allows a user to escape their otherwise limited access. This flaw allows a local, unprivileged user to access virtproxyd without authenticating. Remote users would need to authenticate before they could access it.

A race condition leading to a stack use-after-free flaw was found in libvirt. Due to a bad assumption in the virNetClientIOEventLoop() method, the data pointer to a stack-allocated virNetClientIOEventData structure ended up being used in the virNetClientIOEventFD callback while the data pointer's stack frame was concurrently being "freed" when returning from virNetClientIOEventLoop(). The 'virtproxyd' daemon can be used to trigger requests. If libvirt is configured with fine-grained access control, this issue, in theory, allows a user to escape their otherwise limited access. This flaw allows a local, unprivileged user to access virtproxyd without authenticating. Remote users would need to authenticate before they could access it.

• CVE-2024-2496: fix memory corruption listing interfaces
• CVE-2024-4418: fix stack use-after-free in event loop

These are all security issues fixed in the libvirt-10.3.0-2.1 package on the GA media of openSUSE Tumbleweed.

This update for libvirt fixes the following issues:

• CVE-2024-4418: Fixed a stack use-after-free by ensuring temporary GSource is removed from client event loop. (bsc#1223849)

This update for libvirt fixes the following issues:

Security issue fixed:

• CVE-2024-4418: rpc: ensure temporary GSource is removed from client event loop (bsc#1223849)

Non-security issue fixed:

• libxl: Fix domxml-to-native conversion (bsc#1222584)
• qemu: Fix migration with custom XML (bsc#1226492)

Martin Širokov discovered that libvirt incorrectly handled certain memory operations. A local attacker could possibly use this issue to access virtproxyd without authorization.