CVE-2024-46852

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

dma-buf: heaps: Fix off-by-one in CMA heap fault handler

Until VM_DONTEXPAND was added in commit 1c1914d6e8c6 (dma-buf: heaps: Dont track CMA dma-buf pages under RssFile) it was possible to obtain a mapping larger than the buffer size via mremap and bypass the overflow check in dma_buf_mmap_internal. When using such a mapping to attempt to fault past the end of the buffer, the CMA heap fault handler also checks the fault offset against the buffer size, but gets the boundary wrong by

1. Fix the boundary check so that we dont read off the end of the pages array and insert an arbitrary page in the mapping.

Weakness

A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/007180fcb6cc4a93211d4cc45fef3f5ccccd56ae
• https://git.kernel.org/stable/c/79cce5e81d20fa9ad553be439d665ac3302d3c95
• https://git.kernel.org/stable/c/84175dc5b2c932266a50c04e5ce342c30f817a2f
• https://git.kernel.org/stable/c/e79050882b857c37634baedbdcf7c2047c24cbff
• https://git.kernel.org/stable/c/ea5ff5d351b520524019f7ff7f9ce418de2dad87
• https://git.kernel.org/stable/c/eb7fc8b65cea22f9038c52398c8b22849e9620ea