CVE-2021-47401

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

ipack: ipoctal: fix stack information leak

The tty driver name is used also after registering the driver and must specifically not be allocated on the stack to avoid leaking information to user space (or triggering an oops).

Drivers should not try to encode topology information in the tty device name but this one snuck in through staging without anyone noticing and another driver has since copied this malpractice.

Fixing the ABI is a separate issue, but this at least plugs the security hole.

Weakness

The product exposes a resource to the wrong control sphere, providing unintended actors with inappropriate access to the resource.

Affected Software

Extended Description

Resources such as files and directories may be inadvertently exposed through mechanisms such as insecure permissions, or when a program accidentally operates on the wrong object. For example, a program may intend that private files can only be provided to a specific user. This effectively defines a control sphere that is intended to prevent attackers from accessing these private files. If the file permissions are insecure, then parties other than the user will be able to access those files. A separate control sphere might effectively require that the user can only access the private files, but not any other files on the system. If the program does not ensure that the user is only requesting private files, then the user might be able to access other files on the system. In either case, the end result is that a resource has been exposed to the wrong party.

References

• https://git.kernel.org/stable/c/0a9c36a2e06a249acbed64e8e0b84637c2ad7575
• https://git.kernel.org/stable/c/2725925982dc96a78069cd118ea3d66759bfdad7
• https://git.kernel.org/stable/c/5f6a309a699675680df15d9b6d389114515b4426
• https://git.kernel.org/stable/c/741ea2670e021350e54f491106bdaa22dc50e6a0
• https://git.kernel.org/stable/c/829f13d6079cf7a2465522f39acb43033e9b320d
• https://git.kernel.org/stable/c/8657158a3b68c85234e6da3d8eae33d6183588b7
• https://git.kernel.org/stable/c/a89936cce87d60766a75732a9e7e25c51164f47c
• https://git.kernel.org/stable/c/acb96e782bad427ca4bb1bd94af660acd1462380
• https://git.kernel.org/stable/c/0a9c36a2e06a249acbed64e8e0b84637c2ad7575
• https://git.kernel.org/stable/c/2725925982dc96a78069cd118ea3d66759bfdad7
• https://git.kernel.org/stable/c/5f6a309a699675680df15d9b6d389114515b4426
• https://git.kernel.org/stable/c/741ea2670e021350e54f491106bdaa22dc50e6a0
• https://git.kernel.org/stable/c/829f13d6079cf7a2465522f39acb43033e9b320d
• https://git.kernel.org/stable/c/8657158a3b68c85234e6da3d8eae33d6183588b7
• https://git.kernel.org/stable/c/a89936cce87d60766a75732a9e7e25c51164f47c
• https://git.kernel.org/stable/c/acb96e782bad427ca4bb1bd94af660acd1462380