| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-21694: fs/proc: fix softlockup in __read_vmcore (part 2) |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2025-21694 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.4.279 with commit 803d5a33d5ffdc2d86dcc0cfa01655a330612cdb and fixed in 5.4.290 with commit 84c4ed15626574c9ac6c1039ba9c137a77bcc7f2 |
| Issue introduced in 5.10.221 with commit 70c1835e776c8447c1aca87ddb38cfe764fe756a and fixed in 5.10.234 with commit 80da29deb88a3a907441fc35bb7bac309f31e713 |
| Issue introduced in 5.15.162 with commit e1b160a50c756e0efbea290b9bf5117cb80e8c4b and fixed in 5.15.177 with commit 649b266606bc413407ce315f710c8ce8a88ee30a |
| Issue introduced in 6.1.95 with commit a373ad833a6bfe4bc6cedcf7e56a99cc6fd9a193 and fixed in 6.1.127 with commit 65c367bd9d4f43513c7f837df5753bea9561b836 |
| Issue introduced in 6.6.35 with commit 518fbd644dabb6aedbdd4939c6c9cc1bf651459f and fixed in 6.6.74 with commit a5a2ee8144c3897d37403a69118c3e3dc5713958 |
| Issue introduced in 6.10 with commit 5cbcb62dddf5346077feb82b7b0c9254222d3445 and fixed in 6.12.11 with commit 80828540dad0757b6337c6561d49c81038f38d87 |
| Issue introduced in 6.10 with commit 5cbcb62dddf5346077feb82b7b0c9254222d3445 and fixed in 6.13 with commit cbc5dde0a461240046e8a41c43d7c3b76d5db952 |
| Issue introduced in 4.19.317 with commit 7bdf1d550ddfcd9ab797087421f77b7aceddc8a7 |
| Issue introduced in 6.9.6 with commit e8780e8a0e25dc4c3927f611ec8970d26c0c7369 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-21694 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| fs/proc/vmcore.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/84c4ed15626574c9ac6c1039ba9c137a77bcc7f2 |
| https://git.kernel.org/stable/c/80da29deb88a3a907441fc35bb7bac309f31e713 |
| https://git.kernel.org/stable/c/649b266606bc413407ce315f710c8ce8a88ee30a |
| https://git.kernel.org/stable/c/65c367bd9d4f43513c7f837df5753bea9561b836 |
| https://git.kernel.org/stable/c/a5a2ee8144c3897d37403a69118c3e3dc5713958 |
| https://git.kernel.org/stable/c/80828540dad0757b6337c6561d49c81038f38d87 |
| https://git.kernel.org/stable/c/cbc5dde0a461240046e8a41c43d7c3b76d5db952 |
