CVE-2026-98117

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

cachefiles: Fix potential UAF/KASAN warning

Currently, trace cachefiles coherency() is being passed a pointer to a be64 lain over the coherency data in struct cachefiles xattr so that it can display the first 8 bytes. However, the data is of variable length and could even be 0 bytes. This could lead to a UAF or KASAN warning.

Fix this by making sure the buffer has room for at least 8 bytes and that those 8 bytes are pre-cleared.

Further, those bytes are not 8-byte aligned, so fix the tracepoint to extract the data as four 2-byte words (they are 2-byte aligned) and reassemble the be64. The compiler will convert this into a single 8-byte load where the CPU supports it.