CVE-2026-74424

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

fbcon: fix NULL pointer dereference for a console without vc_data

fbcon_new_modelist() runs when a framebuffer's modelist changes. For each

console mapped to it with fb_display[i].mode set, it reads vc_cons[i].d and

passes the vc_num to fbcon_set_disp(). This assumes a console with a mode

set has a vc_data, but it can be NULL. fbcon_set_disp() sets

fb_display[i].mode before it checks vc_data, and fbcon_deinit() leaves the

mode set after the vc_data is freed. fbcon_new_modelist() then dereferences

the NULL vc_data.

Keep fb_display[i].mode set only while the console has a vc_data. Check

vc_data before setting the mode in fbcon_set_disp(), and clear the mode in

fbcon_deinit(). The existing mode check in fbcon_new_modelist() then skips

such consoles.