CVE-2024-50199
In the Linux kernel, the following vulnerability has been resolved: mm/swapfile: skip HugeTLB pages for unuse_vma I got a bad pud error and lost a 1GB HugeTLB when calling swapoff.
Does this matter?
Lower severity and a low EPSS score (0.22%). Track it; it rarely justifies an emergency change on its own.
Description
In the Linux kernel, the following vulnerability has been resolved: mm/swapfile: skip HugeTLB pages for unuse_vma I got a bad pud error and lost a 1GB HugeTLB when calling swapoff. The problem can be reproduced by the following steps: 1. Allocate an anonymous 1GB HugeTLB and some other anonymous memory. 2. Swapout the above anonymous memory. 3. run swapoff and we will get a bad pud error in kernel message: mm/pgtable-generic.c:42: bad pud 00000000743d215d(84000001400000e7) We can tell that pud_clear_bad is called by pud_none_or_clear_bad in unuse_pud_range() by ftrace. And therefore the HugeTLB pages will never be freed because we lost it from page table. We can skip HugeTLB pages for unuse_vma to fix it.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.22% probability · 13th percentile
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/417d5838ca73c6331ae2fe692fab6c25c00d9a0bPatch
- https://git.kernel.org/stable/c/6ec0fe3756f941f42f8c57156b8bdf2877b2ebafPatch
- https://git.kernel.org/stable/c/7528c4fb1237512ee18049f852f014eba80bbe8dPatch
- https://git.kernel.org/stable/c/ba7f982cdb37ff5a7739dec85d7325ea66fc1496Patch
- https://git.kernel.org/stable/c/bed2b9037806c62166a0ef9a559a1e7e3e1275b8Patch
- https://git.kernel.org/stable/c/e41710f5a61aca9d6baaa8f53908a927dd9e7aa7Patch
- https://git.kernel.org/stable/c/eb66a833cdd2f7302ee05d05e0fa12a2ca32eb87Patch
- https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.