CVE-2026-31614

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

smb: client: fix off-by-8 bounds check in check_wsl_eas()

The bounds check uses (u8 *)ea + nlen + 1 + vlen as the end of the EA
name and value, but ea_data sits at offset sizeof(struct
smb2_file_full_ea_info) = 8 from ea, not at offset 0.  The strncmp()
later reads ea->ea_data[0..nlen-1] and the value bytes follow at
ea_data[nlen+1..nlen+vlen], so the actual end is ea->ea_data + nlen + 1
+ vlen.  Isn't pointer math fun?

The earlier check (u8 *)ea > end - sizeof(*ea) only guarantees the
8-byte header is in bounds, but since the last EA is placed within 8
bytes of the end of the response, the name and value bytes are read past
the end of iov.

Fix this mess all up by using ea->ea_data as the base for the bounds
check.

An "untrusted" server can use this to leak up to 8 bytes of kernel heap
into the EA name comparison and influence which WSL xattr the data is
interpreted as.