{"id":"CVE-2026-64318","title":"In the Linux kernel, the following vulnerability has been resolved:\n\npartitions: aix: bound the pp_count scan to the ppe array\n\naix_partition() reads the physical volume descriptor into a fixed-size\nstruct pvd and then scans its physical…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\npartitions: aix: bound the pp_count scan to the ppe array\n\naix_partition() reads the physical volume descriptor into a fixed-size\nstruct pvd and then scans its physical…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","published":"2026-07-25","updated":"2026-07-27","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64318","references":[{"url":"https://git.kernel.org/stable/c/09861651617ba0fec089e8b9477439e68398c110","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2dc0bfd2fe355fb930de63c2f2eb8ced8570c579","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/44f37ee92fdcd377c41bdf6a31cdd8cc7d4c410e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4671bb74bba05fdd4acf670a35758c29e8c97b83","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5eacdb1967378f5e5591cd27a2d8cdee2df1a599","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b5e9c09309e18fd9839ad007c238120353ca0cc4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ce93228e2193a17d2c58b656e439bb39fe5c3af8","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fd94a779020f2ecc8b2607f4c20b34acb1763b9a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00164,"epssPercentile":0.04926,"ingestedAt":"2026-07-27T06:16:50.453Z","slug":"CVE-2026-64318","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\npartitions: aix: bound the pp_count scan to the ppe array\n\naix_partition() reads the physical volume descriptor into a fixed-size\nstruct pvd and then scans its physical-partition-extent array:\n\n\tint numpps = be16_to_cpu(pvd->pp_count);\n\t...\n\tfor (i = 0; i < numpps; i += 1) {\n\t\tstruct ppe *p = pvd->ppe + i;\n\t\t...\n\t\tlp_ix = be16_to_cpu(p->lp_ix);\n\npvd points at a single kmalloc()'d struct pvd whose ppe[] member holds a\nfixed ARRAY_SIZE(pvd->ppe) (1016) entries, but the loop runs up to the\non-disk pp_count.  pp_count is an unvalidated __be16 read straight from\nthe descriptor, so a crafted AIX image with pp_count larger than 1016\ndrives the loop to read pvd->ppe[i] past the end of the allocation (up\nto 65535 entries, ~2 MB out of bounds).\n\nThe partition scan runs without mounting anything, when a block device\nwith a crafted AIX/IBM partition table appears (an attacker-supplied\nimage attached with losetup -P, or a device auto-scanned by udev), via\nmsdos_partition() -> aix_partition().\n\nClamp the scan to the number of entries the ppe[] array can hold.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}