CVE-2025-21694

Vulnerability Description

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.

CVSS Score

Affected Products

References

• https://git.kernel.org/stable/c/649b266606bc413407ce315f710c8ce8a88ee30aPatch
• https://git.kernel.org/stable/c/65c367bd9d4f43513c7f837df5753bea9561b836Patch
• https://git.kernel.org/stable/c/80828540dad0757b6337c6561d49c81038f38d87Patch
• https://git.kernel.org/stable/c/80da29deb88a3a907441fc35bb7bac309f31e713Patch
• https://git.kernel.org/stable/c/84c4ed15626574c9ac6c1039ba9c137a77bcc7f2Patch
• https://git.kernel.org/stable/c/a5a2ee8144c3897d37403a69118c3e3dc5713958Patch
• https://git.kernel.org/stable/c/cbc5dde0a461240046e8a41c43d7c3b76d5db952Patch
• https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
• https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
• https://cert-portal.siemens.com/productcert/html/ssa-265688.html
• https://cert-portal.siemens.com/productcert/html/ssa-355557.html
• https://cert-portal.siemens.com/productcert/html/ssa-398330.html