Description

In the Linux kernel, the following vulnerability has been resolved: arm64/sme: Set new vector length before reallocating As part of fixing the allocation of the buffer for SVE state when changing SME vector length we introduced an immediate reallocation of the SVE state, this is also done when changing the SVE vector length for consistency. Unfortunately this reallocation is done prior to writing the new vector length to the task struct, meaning the allocation is done with the old vector length and can lead to memory corruption due to an undersized buffer being used. Move the update of the vector length before the allocation to ensure that the new vector length is taken into account. For some reason this isn't triggering any problems when running tests on the arm64 fixes branch (even after repeated tries) but is triggering issues very often after merge into mainline.

Weaknesses 1

Affected Products 3

References 3

• git.kernel.org https://git.kernel.org/stable/c/05d881b85b48c7ac6a7c92ce00aa916c4a84d052
  Patch
• git.kernel.org https://git.kernel.org/stable/c/356e711640aea6ed145da9407499388b45264cb4
  Patch
• git.kernel.org https://git.kernel.org/stable/c/807ada0e4aa3c9090c66009a99fa530c462012c9
  Patch

Remediation

• git.kernel.org https://git.kernel.org/stable/c/05d881b85b48c7ac6a7c92ce00aa916c4a84d052
  Patch
• git.kernel.org https://git.kernel.org/stable/c/356e711640aea6ed145da9407499388b45264cb4
  Patch
• git.kernel.org https://git.kernel.org/stable/c/807ada0e4aa3c9090c66009a99fa530c462012c9
  Patch