Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

dm-pcache: bound the persisted tail-position offset

cache_pos_decode() takes the persisted key_tail and dirty_tail seg_off from the cache device and addresses within the segment with it. A seg_off at or past the segment data_size, controllable by whoever supplies the device (CAP_SYS_ADMIN), reads past the segment data.

Reject a decoded seg_off that is not below the segment data_size.