CVE-2021-47026

Technical Description

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

RDMA/rtrs-clt: destroy sysfs after removing session from active list

A session can be removed dynamically by sysfs interface "remove_path" that

eventually calls rtrs_clt_remove_path_from_sysfs function. The current

rtrs_clt_remove_path_from_sysfs first removes the sysfs interfaces and

frees sess->stats object. Second it removes the session from the active

list.

Therefore some functions could access non-connected session and access the

freed sess->stats object even-if they check the session status before

accessing the session.

For instance rtrs_clt_request and get_next_path_min_inflight check the

session status and try to send IO to the session. The session status

could be changed when they are trying to send IO but they could not catch

the change and update the statistics information in sess->stats object,

and generate use-after-free problem.

(see: "RDMA/rtrs-clt: Check state of the rtrs_clt_sess before reading i

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References