CVE-2022-49771: 
Linux Kernel vulnerability analysis and mitigation

CVE-2022-49771 is a vulnerability discovered in the Linux kernel's device mapper (dm) ioctl functionality. The issue was disclosed on May 1, 2025, affecting the Linux kernel's listversions operation when module loading takes place. This vulnerability specifically relates to a race condition that occurs during the listversions operation (NVD, Wiz).

The vulnerability stems from a race condition between two dmtargetiterate calls where no lock is held, allowing target modules to be loaded during this interval. The first call estimates required space using dmtargetiterate(listversiongetneeded, &needed), followed by a second call to fill the space using dmtargetiterate(listversiongetinfo, &iter_info). While the code attempts to handle buffer overflow situations, the implementation is incorrect, potentially leading to data truncation. The vulnerability has been assigned a CVSS v3.1 Base Score of 5.5 with attack vector: Local (Red Hat).

When exploited, this vulnerability can result in partial truncation of results due to incorrect buffer size calculations. The issue affects the kernel's device mapper functionality, potentially impacting systems that rely on device mapping operations (Wiz).

The vulnerability has been fixed by modifying the buffer handling logic to ensure proper space allocation and implementing correct overflow handling. The fix involves setting iterinfo.end = (char *)vers + needed to guarantee that the second dmtargetiterate call will only write up to the needed buffer size. Additionally, a fix for listversiongetneeded was implemented to add strlen(tt->name) + 1 to the needed size instead of just strlen(tt->name) (NVD).