CVE-2026-63939

01/תיאור (מקור, אנגלית)

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Compute the correct max length of the in-GHCB scratch area When setting the length of the GHCB scratch area, and the area is in the GHCB shared buffer, set the effective length of the scratch area to the max possible size given the start of the guest-provided pointer, and the end of the shared buffer. The code was "fine" when first introduced, as KVM doesn't consult the length of the buffer when emulating MMIO, because the passed in @len always specifies the *max* size required. But for PSC requests, the incoming @len is just the minimum length (to process the header), and KVM needs to know the full size of the scratch area to avoid buffer overflows (spoiler alert). Opportunistically rename @len => @min_len to better reflect its role.

02/מוצרים מושפעים

linux: linux kernel

03/קישורים4

• git.kernel.org/stable/c/5867d7e202e09f037cefe77f7af4413c7c0fa088 Patch
• git.kernel.org/stable/c/6644565527c4c5f507088b1c9ddf72de47790b68 Patch
• git.kernel.org/stable/c/6ca9400d36005ffdca25f80186bea781c7e1dc4c Patch
• git.kernel.org/stable/c/9f0a9e780f02c02d025a190f1885e1d1d73b87bd Patch