CVE-2026-89632

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

smb: client: fix use-before-check of ReparseDataLength in reparse_buf_ptr()

reparse_buf_ptr() reads buf->ReparseDataLength before checking that

count covers the full fixed header:

buf = (struct reparse_data_buffer *)((u8 *)io + off);

len = sizeof(*buf); /* 8 bytes */

rdlen = le16_to_cpu(buf->ReparseDataLength); /* offset 4, 2 bytes */

if (count < len || count < rdlen + len) /* check comes after */

struct reparse_data_buffer has ReparseDataLength at offset 4. If a

server returns OutputCount < 6, the read at offset 4-5 reaches past

the end of the received data. The off+count bounds against iov_len

were already validated, but that does not protect against count being

smaller than sizeof(*buf).

Split the check: verify count >= sizeof(*buf) before reading

ReparseDataLength, then verify count covers the data region.