Description
In the Linux kernel, the following vulnerability has been resolved: drm/vmwgfx: bound DMA command body size against suffix pointer vmw_cmd_dma() locates the DMA suffix at (unsigned long) &cmd->body + header->size - sizeof(*suffix) without checking that header->size is large enough to contain both cmd->body and the suffix. An undersized header makes the suffix pointer underflow back into the previous command in the bounce buffer. The verifier later writes suffix->maximumOffset, clobbering verified fields of an already-relocated earlier command -- a TOCTOU on the device-visible command stream that lets one command rewrite another's GMR id, surface id, or other authenticated fields. Reject the command if the body is too small for the suffix to fit.
References8
- git.kernel.org/stable/c/036e16ada95389bdc30f41068af04c1d0872fad0
- git.kernel.org/stable/c/7e40e6120fb232a10b543ffd994e5c6d8f3a2cc6
- git.kernel.org/stable/c/9759da60e38d7b9db44dc92713e4e0391883d221
- git.kernel.org/stable/c/a4a37080a5ac777b59306cfcdf854cc05d7604d4
- git.kernel.org/stable/c/d5d7ada4e1296b00d89fe82b2ca850cc7809d6f7
- git.kernel.org/stable/c/eb20f418933bea53375843b27b4022c1810be63b
- git.kernel.org/stable/c/f4f1db96bfd68b81053693ba53405b6f510ac16c
- git.kernel.org/stable/c/fcd1e56e7816b31a1050ccc67df722b20f6bb15d
Metrics
- CVSS 3.1
-
8.8
HIGH
Score source: CNA
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H - EPSS — exploit probability
- 0% percentile: 3 · as of 11 November 2026
Could this be exploited in your environment?
A patch closes the known hole. A penetration test shows what an attacker can still reach — with proof.