CVE-2026-99083
Description
In the Linux kernel, the following vulnerability has been resolved: ksmbd: fix heap out-of-bounds write in krb5_authenticate() In krb5_authenticate(), out_len is calculated to determine available headroom in response_buf for the incoming Kerberos AP-REP token. However, when SMB2_SESSION_SETUP is processed as a non-first element of a compounded SMB2 request, the calculation omits work->next_smb2_rsp_hdr_off. This causes out_len to overstate remaining buffer headroom by the cumulative size of prior responses in the compound chain. Consequently, the length check in ksmbd_krb5_authenticate() (*out_len <= resp->spnego_blob_len) passes erroneously, allowing memcpy() to write the AP-REP blob past the end of response_buf into adjacent kernel heap memory. Fix this by subtracting work->next_smb2_rsp_hdr_off when computing out_len, ensuring it accurately reflects physical remaining buffer space.
How to fix
- Linux Linuxa07dfb33112a42437f9d2d0bfd35c68575257381, 1f73a6d40f4d1bae4f3491c0ec1ea8ee6ce035ff, 59c6dcc5dd9dafe764ca0d40525933b2be69b059, 80af1bde97d5a85ad6f2c40ca894ccc8fa75a27a, 517404e157395d0f8da125ca956c566895dfcd06, 4722d06b2907585074252061b1024a696c1cfc23, 23a0be6a84a38ac169eeab49017934e8e27c65f0, 5.15.224, 6.1.191, 6.5 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| Linux Linux | 676392184785ace61e939831e7ca44a03d438c3b ≤ v < a07dfb33112a42437f9d2d0bfd35c68575257381, ef572ffa8eb44111eed2925fbb2adca78bdcbf61 ≤ v < 1f73a6d40f4d1bae4f3491c0ec1ea8ee6ce035ff, 98422bdd4cb3ca4d08844046f6507d7ec2c2b8d8 ≤ v < 59c6dcc5dd9dafe764ca0d40525933b2be69b059, 98422bdd4cb3ca4d08844046f6507d7ec2c2b8d8 ≤ v < 80af1bde97d5a85ad6f2c40ca894ccc8fa75a27a, 98422bdd4cb3ca4d08844046f6507d7ec2c2b8d8 ≤ v < 517404e157395d0f8da125ca956c566895dfcd06, 98422bdd4cb3ca4d08844046f6507d7ec2c2b8d8 ≤ v < 4722d06b2907585074252061b1024a696c1cfc23, 98422bdd4cb3ca4d08844046f6507d7ec2c2b8d8 ≤ v < 23a0be6a84a38ac169eeab49017934e8e27c65f0, 2ba03cecb12ac7ac9e0170e251543c56832d9959, 5.15.145 ≤ v < 5.15.224, 6.1.40 ≤ v < 6.1.191, 6.4.5 ≤ v < 6.5, 6.5 | a07dfb33112a42437f9d2d0bfd35c68575257381, 1f73a6d40f4d1bae4f3491c0ec1ea8ee6ce035ff, 59c6dcc5dd9dafe764ca0d40525933b2be69b059, 80af1bde97d5a85ad6f2c40ca894ccc8fa75a27a, 517404e157395d0f8da125ca956c566895dfcd06, 4722d06b2907585074252061b1024a696c1cfc23, 23a0be6a84a38ac169eeab49017934e8e27c65f0, 5.15.224, 6.1.191, 6.5 |
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