Executive brief
A vulnerability in the Linux kernel's handling of AIX partition tables could allow a system crash or information leakage. When the system scans a specially crafted storage device or disk image, it may read data beyond the intended memory boundaries. This occurs automatically when a device is attached or scanned by the system, potentially impacting system stability or security.
Technical details
An out-of-bounds read vulnerability exists in block/partitions/aix.c within the aix_partition() function. The function reads a physical volume descriptor (PVD) into a fixed-size structure but uses an unvalidated 16-bit 'pp_count' value from the disk to iterate through the 'ppe' array. If 'pp_count' exceeds the fixed array size of 1016, the kernel performs out-of-bounds reads of up to ~2 MB. This can be triggered during partition scanning (e.g., via udev or losetup -P) without requiring the device to be mounted. The fix implements a check to clamp the scan loop to the actual size of the ppe array.
Affected products
- Linux Linux Kernel 6ceea22bbbc8 to 09861651617ba0fec089e8b9477439e68398c110
Timeline
- 2026-06-07: other: Vulnerability reported/authored by Bryam Vargas
- 2026-07-25: advisory: CVE-2026-64318 published
- 2026-07-24: patched: Fix committed to stable kernel tree
References
- https://git.kernel.org/stable/c/09861651617ba0fec089e8b9477439e68398c110
- https://git.kernel.org/stable/c/2dc0bfd2fe355fb930de63c2f2eb8ced8570c579
- https://git.kernel.org/stable/c/44f37ee92fdcd377c41bdf6a31cdd8cc7d4c410e
- https://git.kernel.org/stable/c/4671bb74bba05fdd4acf670a35758c29e8c97b83
- https://git.kernel.org/stable/c/5eacdb1967378f5e5591cd27a2d8cdee2df1a599
- https://git.kernel.org/stable/c/b5e9c09309e18fd9839ad007c238120353ca0cc4
- https://git.kernel.org/stable/c/ce93228e2193a17d2c58b656e439bb39fe5c3af8