In the Linux kernel, the following vulnerability has been resolved:
dm era: fix out-of-bounds memory access for non-zero start sector
dm-era tracks writes in target-relative blocks, but era_map() calculates
the writeset block before applying the target offset. Tables with a
non-zero start sector can therefore pass an absolute mapped-device block
to metadata_current_marked().
If the absolute block is beyond the current writeset size,
writeset_marked() tests past the end of the in-core bitset. KASAN reports
this as a vmalloc-out-of-bounds access.
Apply the target offset before calculating the era block so writeset
lookups use the target-relative block number.
