Use After Free Affecting kernel-debug-core package, versions *

Note: Versions mentioned in the description apply only to the upstream kernel-debug-core package and not the kernel-debug-core package as distributed by RHEL. See How to fix? for RHEL:8 relevant fixed versions and status.

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

xen: privcmd: Fix possible access to a freed kirqfd instance

Nothing prevents simultaneous ioctl calls to privcmd_irqfd_assign() and privcmd_irqfd_deassign(). If that happens, it is possible that a kirqfd created and added to the irqfds_list by privcmd_irqfd_assign() may get removed by another thread executing privcmd_irqfd_deassign(), while the former is still using it after dropping the locks.

This can lead to a situation where an already freed kirqfd instance may be accessed and cause kernel oops.

Use SRCU locking to prevent the same, as is done for the KVM implementation for irqfds.

• https://access.redhat.com/security/cve/CVE-2024-46762
• https://git.kernel.org/stable/c/112fd2f02b308564724b8e81006c254d20945c4b
• https://git.kernel.org/stable/c/611ff1b1ae989a7bcce3e2a8e132ee30e968c557
• https://git.kernel.org/stable/c/e997b357b13a7d95de31681fc54fcc34235fa527