In the Linux kernel, the following vulnerability has been resolved: fs/proc: fix softlockup in __read_vmcore (part 2) Since commit 5cbcb62dddf5 ("fs/proc: fix softlockup in __read_vmcore") the number of softlockups in __read_vmcore at kdump time have gone down, but they still happen sometimes. In a memory constrained environment like the kdump image, a softlockup is not just a harmless message, but it can interfere with things like RCU freeing memory, causing the crashdump to get stuck. The second loop in __read_vmcore has a lot more opportunities for natural sleep points, like scheduling out while waiting for a data write to happen, but apparently that is not always enough. Add a cond_resched() to the second loop in __read_vmcore to (hopefully) get rid of the softlockups.
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2025021259-CVE-2025-21694-f5ca@gregkh/T
This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2025:6966 https://access.redhat.com/errata/RHSA-2025:6966