In the Linux kernel, the following vulnerability has been resolved: fbdev: modedb: fix a possible UAF in fb_find_mode() If mode_option is NULL, it is assigned from mode_option_buf: if (!mode_option) { fb_get_options(NULL, &mode_…

Overview

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

fbdev: modedb: fix a possible UAF in fb_find_mode()

If mode_option is NULL, it is assigned from mode_option_buf:

if (!mode_option) { fb_get_options(NULL, &mode_option_buf); mode_option = mode_option_buf; }

Later, name is assigned from mode_option:

const char *name = mode_option;

However, mode_option_buf is freed before name is no longer used:

kfree(mode_option_buf);

while name is still accessed by:

if ((name_matches(db[i], name, namelen) ||

Since name aliases mode_option_buf, this may result in a use-after-free.

Fix this by extending the lifetime of mode_option_buf until the end of the function by using scope-based resource management for cleanup.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.