CVE-2024-53148

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

comedi: Flush partial mappings in error case

If some remap_pfn_range() calls succeeded before one failed, we still have buffer pages mapped into the userspace page tables when we drop the buffer reference with comedi_buf_map_put(bm). The userspace mappings are only cleaned up later in the mmap error path.

Fix it by explicitly flushing all mappings in our VMA on the error path.

See commit 79a61cc3fc04 ("mm: avoid leaving partial pfn mappings around in error case").

This vulnerability does not present a security risk to Red Hat Enterprise Linux because the Comedi subsystem is not enabled in supported kernel configurations. The issue stems from improperly flushed page table entries during mapping failures within data acquisition drivers, which could otherwise allow a local user to cause a kernel crash or corrupt system memory. Since the underlying framework and drivers are excluded from Red Hat kernel builds, standard deployments remain unexposed.