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.
References
- https://git.kernel.org/stable/c/1fcb5e29dd7a5b85adb9d8b539911741d878e829
- https://git.kernel.org/stable/c/7e1822f83c5a1ee7b4a19e98edde8770a10b4c71
- https://git.kernel.org/stable/c/9946a7176bd8c25ddd6e5f1799c54e572ee6bf0f
- https://git.kernel.org/stable/c/a868196f03c2b19418ae3d2b69e195d668a271e5
- https://git.kernel.org/stable/c/bafe3e720cdac38cd7ea4eb7852a8f2dbe1bbfe6
- https://git.kernel.org/stable/c/db5f9b4601f0012038e5a2628aedec2f47933380
- https://git.kernel.org/stable/c/e3ffa8e492e5cdee62d916ee3e9244ccce2b73c5
- https://git.kernel.org/stable/c/fe94a0b14010a3c267ff9a2508afb4f27ff1c5bf