nvmet-auth: reject short AUTH_RECEIVE buffers

Overview

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

nvmet-auth: reject short AUTH_RECEIVE buffers

nvmet_execute_auth_receive() trusts the AUTH_RECEIVE allocation length after checking only that it is nonzero and matches the transfer length. In the SUCCESS1 and FAILURE1/default states, that lets a remote NVMe-oF initiator reach the fixed-size DH-HMAC-CHAP response builders with a kmalloc() buffer shorter than the response, so nvmet_auth_success1() and nvmet_auth_failure1() write past the allocation; both only WARN_ON the short length and then format the message anyway.

Impact: A remote NVMe-oF initiator with access to an auth-enabled target can trigger a 16-byte heap out-of-bounds write via a one-byte AUTH_RECEIVE allocation length.

Compute the minimum response length for the current DH-HMAC-CHAP step in nvmet_auth_receive_data_len() and report a zero data length when the host-supplied allocation length is shorter, so the existing zero-length check in nvmet_execute_auth_receive() rejects the command before any builder runs. The SUCCESS1 minimum is sizeof(struct nvmf_auth_dhchap_success1_data) plus the HMAC hash length, because the response hash is written into the rval[] flexible-array tail, so the minimum is state dependent rather than a flat sizeof. CHALLENGE keeps its existing variable-length guard in nvmet_auth_challenge().

This is reachable only when in-band DH-HMAC-CHAP authentication is configured on the target.

Affected

• Linux >= db1312dd95488b5e6ff362ff66fcf953a46b1821 < 80bf7b7f676e3987bbe06af3c359bd56ac91a5a9
• Linux >= db1312dd95488b5e6ff362ff66fcf953a46b1821 < 2eaa3ad450141cfcf187bb43cb8335eb336b5f87
• Linux >= db1312dd95488b5e6ff362ff66fcf953a46b1821 < bc111698b46e43eddd8664cceaa621cd559e99a0
• Linux >= db1312dd95488b5e6ff362ff66fcf953a46b1821 < 779575bc35c687697ba69e904f2cd22e60112534
• Linux 6.0

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.