{"id":"CVE-2025-21694","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc: fix softlockup in __read_vmcore (part 2)\n\nSince commit 5cbcb62dddf5 (\"fs/proc: fix softlockup in __read_vmcore\") the\nnumber of softlockups in __read_vmcore at …","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc: fix softlockup in __read_vmcore (part 2)\n\nSince commit 5cbcb62dddf5 (\"fs/proc: fix softlockup in __read_vmcore\") the\nnumber of softlockups in __read_vmcore at …","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 4.19.317, < 4.20","linux_kernel >= 5.4.279, < 5.4.290","linux_kernel >= 5.10.221, < 5.10.234","linux_kernel >= 5.15.162, < 5.15.177","linux_kernel >= 6.1.95, < 6.1.127","linux_kernel >= 6.6.35, < 6.6.74","linux_kernel >= 6.9.6, < 6.12.11","linux_kernel = 6.13"],"patched":["linux_kernel 6.12.11"],"published":"2025-02-12","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:17:27.130","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-21694","references":[{"url":"https://git.kernel.org/stable/c/649b266606bc413407ce315f710c8ce8a88ee30a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/65c367bd9d4f43513c7f837df5753bea9561b836","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/80828540dad0757b6337c6561d49c81038f38d87","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/80da29deb88a3a907441fc35bb7bac309f31e713","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/84c4ed15626574c9ac6c1039ba9c137a77bcc7f2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a5a2ee8144c3897d37403a69118c3e3dc5713958","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/cbc5dde0a461240046e8a41c43d7c3b76d5db952","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-355557.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00242,"epssPercentile":0.15321,"ingestedAt":"2026-10-15T03:30:12.784Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2025-10-01T20:08:56.110006Z"},"slug":"CVE-2025-21694","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc: fix softlockup in __read_vmcore (part 2)\n\nSince commit 5cbcb62dddf5 (\"fs/proc: fix softlockup in __read_vmcore\") the\nnumber of softlockups in __read_vmcore at kdump time have gone down, but\nthey still happen sometimes.\n\nIn a memory constrained environment like the kdump image, a softlockup is\nnot just a harmless message, but it can interfere with things like RCU\nfreeing memory, causing the crashdump to get stuck.\n\nThe second loop in __read_vmcore has a lot more opportunities for natural\nsleep points, like scheduling out while waiting for a data write to\nhappen, but apparently that is not always enough.\n\nAdd a cond_resched() to the second loop in __read_vmcore to (hopefully)\nget rid of the softlockups.\n\n## Affected\n\n- `linux_kernel >= 4.19.317, < 4.20`\n- `linux_kernel >= 5.4.279, < 5.4.290`\n- `linux_kernel >= 5.10.221, < 5.10.234`\n- `linux_kernel >= 5.15.162, < 5.15.177`\n- `linux_kernel >= 6.1.95, < 6.1.127`\n- `linux_kernel >= 6.6.35, < 6.6.74`\n- `linux_kernel >= 6.9.6, < 6.12.11`\n- `linux_kernel = 6.13`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.12.11`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}