mm/swapfile: skip HugeTLB pages for unuse_vma
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
Version range not reported
- Linux Linux
2.6.36
References 7
git.kernel.org
- stable/c/ba7f982cdb37ff5a7739dec85d7325ea66fc1496
- stable/c/417d5838ca73c6331ae2fe692fab6c25c00d9a0b
- stable/c/e41710f5a61aca9d6baaa8f53908a927dd9e7aa7
- stable/c/6ec0fe3756f941f42f8c57156b8bdf2877b2ebaf
- stable/c/bed2b9037806c62166a0ef9a559a1e7e3e1275b8
- stable/c/eb66a833cdd2f7302ee05d05e0fa12a2ca32eb87
- stable/c/7528c4fb1237512ee18049f852f014eba80bbe8d