Описание
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.
A flaw was found in the Linux kernel's dm-pcache component. A local attacker with CAP_SYS_ADMIN capabilities can exploit this vulnerability by supplying a specially crafted cache device. The seg_num value, which dictates the size of cache segments, is not adequately validated against the actual device size. This oversight can lead to an out-of-bounds write of 12 KiB into the kernel heap during table load, potentially resulting in a denial of service or other system compromise.
Ссылки на источники
Дополнительная информация
Статус:
EPSS
5.7 Medium
CVSS3
Связанные уязвимости
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.
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.
In the Linux kernel, the following vulnerability has been resolved: d ...
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.
EPSS
5.7 Medium
CVSS3