CVE-2026-97565smb: client: reject short READ responses in CIFSSMBRead()

Official description

In the Linux kernel, the following vulnerability has been resolved: smb: client: reject short READ responses in CIFSSMBRead() CIFSSMBRead() reads DataLengthHigh, DataLength and DataOffset out of the READ_RSP returned by the server without first checking that a whole READ_RSP was actually received. The length of the response is recorded in rsp_iov.iov_len, but nothing constrains it to be at least read_rsp_size before those fields are dereferenced. A malicious or compromised SMB1 server can return a response shorter than the READ_RSP header, so that parsing the header itself reads past the end of the receive buffer. SMB1 is not negotiated by default; reaching this code requires an explicit vers=1.0 mount. Reject the response unless it is at least read_rsp_size bytes long.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/0f1f77b821506a4dacab6ce7d29cf9e0c26f14cd
• https://git.kernel.org/stable/c/aaa221c1b1d288845b55e9c366e5ef608dfff49d
• https://git.kernel.org/stable/c/e6142a8bfc230c7263eb8b0475249c958ce49367