Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: dm-pcache: validate on-media seg_num against the cache device size seg_num is read from the crc32c-only superblock, so whoever supplies the cache device on a table load (CAP_SYS_ADMIN) controls it. It sizes cache->segments[] and is the value every later on-media segment id is bounded against, yet it is never checked against the device. Because cache_dev->mapping is the direct map of the pmem, CACHE_DEV_SEGMENT() for a segment id past the device resolves to ordinary kernel memory beyond the mapping; a new-cache init reaching such an id has cache_seg_init() -> cache_dev_zero_range() memset() 12 KiB over that memory -- an out-of-bounds write into the kernel heap at table load. A zero seg_num makes the segment allocations ZERO_SIZE_PTR. Reject a seg_num that is zero, larger than the device can hold, or larger than PCACHE_CACHE_SEGS_MAX before it is used.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 before 91b93fe5cf4d62d5ecc642a6c8f15a3c11b00e3c; affected 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 before e889c0ee81165fc90aad2979b51f930f77895703; affected 1d57628ff95b32d5cfa8d8f50e07690c161e9cf0 before 62d92e45abe9e087370f9fc5d876b95673aced34 |
| Linux / Linux | affected 6.18; unaffected 0 before 6.18; unaffected 6.18.50 through 6.18.*; unaffected 7.2.4 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.