CVE-2024-38659

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

enic: Validate length of nl attributes in enic_set_vf_port

enic_set_vf_port assumes that the nl attribute IFLA_PORT_PROFILE is of length PORT_PROFILE_MAX and that the nl attributes IFLA_PORT_INSTANCE_UUID, IFLA_PORT_HOST_UUID are of length PORT_UUID_MAX. These attributes are validated (in the function do_setlink in rtnetlink.c) using the nla_policy ifla_port_policy. The policy defines IFLA_PORT_PROFILE as NLA_STRING, IFLA_PORT_INSTANCE_UUID as NLA_BINARY and IFLA_PORT_HOST_UUID as NLA_STRING. That means that the length validation using the policy is for the max size of the attributes and not on exact size so the length of these attributes might be less than the sizes that enic_set_vf_port expects. This might cause an out of bands read access in the memcpys of the data of these attributes in enic_set_vf_port.

Weakness

The product receives input that is expected to specify a quantity (such as size or length), but it does not validate or incorrectly validates that the quantity has the required properties.

Affected Software

Extended Description

Specified quantities include size, length, frequency, price, rate, number of operations, time, and others. Code may rely on specified quantities to allocate resources, perform calculations, control iteration, etc.

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.

References

• https://git.kernel.org/stable/c/25571a12fbc8a1283bd8380d461267956fd426f7
• https://git.kernel.org/stable/c/2b649d7e0cb42a660f0260ef25fd55fdc9c6c600
• https://git.kernel.org/stable/c/3c0d36972edbe56fcf98899622d9b90ac9965227
• https://git.kernel.org/stable/c/7077c22f84f41974a711604a42fd0e0684232ee5
• https://git.kernel.org/stable/c/aee1955a1509a921c05c70dad5d6fc8563dfcb31
• https://git.kernel.org/stable/c/ca63fb7af9d3e531aa25f7ae187bfc6c7166ec2d
• https://git.kernel.org/stable/c/e8021b94b0412c37bcc79027c2e382086b6ce449
• https://git.kernel.org/stable/c/f6638e955ca00c489894789492776842e102af9c
• https://git.kernel.org/stable/c/25571a12fbc8a1283bd8380d461267956fd426f7
• https://git.kernel.org/stable/c/2b649d7e0cb42a660f0260ef25fd55fdc9c6c600
• https://git.kernel.org/stable/c/3c0d36972edbe56fcf98899622d9b90ac9965227
• https://git.kernel.org/stable/c/7077c22f84f41974a711604a42fd0e0684232ee5
• https://git.kernel.org/stable/c/aee1955a1509a921c05c70dad5d6fc8563dfcb31
• https://git.kernel.org/stable/c/ca63fb7af9d3e531aa25f7ae187bfc6c7166ec2d
• https://git.kernel.org/stable/c/e8021b94b0412c37bcc79027c2e382086b6ce449
• https://git.kernel.org/stable/c/f6638e955ca00c489894789492776842e102af9c
• https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html