Description

In the Linux kernel, the following vulnerability has been resolved: drm/xe/migrate: prevent infinite recursion If the buf + offset is not aligned to XE_CAHELINE_BYTES we fallback to using a bounce buffer. However the bounce buffer here is allocated on the stack, and the only alignment requirement here is that it's naturally aligned to u8, and not XE_CACHELINE_BYTES. If the bounce buffer is also misaligned we then recurse back into the function again, however the new bounce buffer might also not be aligned, and might never be until we eventually blow through the stack, as we keep recursing. Instead of using the stack use kmalloc, which should respect the power-of-two alignment request here. Fixes a kernel panic when triggering this path through eudebug. v2 (Stuart): - Add build bug check for power-of-two restriction - s/EINVAL/ENOMEM/ (cherry picked from commit 38b34e928a08ba594c4bbf7118aa3aadacd62fff)

Weaknesses 1

Affected Products 2

References 2

• git.kernel.org https://git.kernel.org/stable/c/89f511c024879c5812cc0c010a6663b5e49950f3
  Patch
• git.kernel.org https://git.kernel.org/stable/c/9d7a1cbebbb691891671def57407ba2f8ee914e8
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/89f511c024879c5812cc0c010a6663b5e49950f3
  Patch
• git.kernel.org https://git.kernel.org/stable/c/9d7a1cbebbb691891671def57407ba2f8ee914e8
  Patch