CVE-2023-53178

/// Technical description

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

mm: fix zswap writeback race condition

The zswap writeback mechanism can cause a race condition resulting in

memory corruption, where a swapped out page gets swapped in with data that

was written to a different page.

The race unfolds like this:

1. a page with data A and swap offset X is stored in zswap

2. page A is removed off the LRU by zpool driver for writeback in

zswap-shrink work, data for A is mapped by zpool driver

3. user space program faults and invalidates page entry A, offset X is

considered free

4. kswapd stores page B at offset X in zswap (zswap could also be

full, if so, page B would then be IOed to X, then skip step 5.)

5. entry A is replaced by B in tree->rbroot, this doesn't affect the

local reference held by zswap-shrink work

6. zswap-shrink work writes back A at X, and frees zswap entry A

7. swapin of slot X brings A in memory instead of B

The fix:

Once the swap page cache has been al

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References