CVE-2024-49924

Description

In the Linux kernel, the following vulnerability has been resolved: fbdev: pxafb: Fix possible use after free in pxafb_task() In the pxafb_probe function, it calls the pxafb_init_fbinfo function, after which &fbi->task is associated with pxafb_task. Moreover, within this pxafb_init_fbinfo function, the pxafb_blank function within the &pxafb_ops struct is capable of scheduling work. If we remove the module which will call pxafb_remove to make cleanup, it will call unregister_framebuffer function which can call do_unregister_framebuffer to free fbi->fb through put_fb_info(fb_info), while the work mentioned above will be used. The sequence of operations that may lead to a UAF bug is as follows: CPU0 CPU1 | pxafb_task pxafb_remove | unregister_framebuffer(info) | do_unregister_framebuffer(fb_info) | put_fb_info(fb_info) | // free fbi->fb | set_ctrlr_state(fbi, state) | __pxafb_lcd_power(fbi, 0) | fbi->lcd_power(on, &fbi->fb.var) | //use fbi->fb Fix it by ensuring that the work is canceled before proceeding with the cleanup in pxafb_remove. Note that only root user can remove the driver at runtime.

Gravité et risque d'exploitation

CVE-2024-49924 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.25 %, ce qui la place devant 15.1 % des CVE référencées.

Que faire ?

• Vérifiez si Linux (versions <e657fa2df4429f3805a9b3e47fb1a4a1b02a72bd, <=6.1.*, 6.12, <a3a855764dbacbdb1cc51e15dc588f2d21c93e0e, <=6.11.*, 5.4.285, 0, <2.6.27, 9f17f2874834f4cdbe48cc05676d8f7558793204, <aaadc0cb05c999ccd8898a03298b7e5c31509b08, <=5.10.*, <=6.6.*, 6.6.55, <6d0a07f68b66269e167def6c0b90a219cd3e7473, 6.11.3, <fdda354f60a576d52dcf90351254714681df4370, <=5.4.*, <4cda484e584be34d55ee17436ebf7ad11922b97a, <=4.19.*, 6.1.113, 4.19.323, <3c0d416eb4bef705f699213cee94bf54b6acdacd, <=*, <=5.15.*, <4a6921095eb04a900e0000da83d9475eb958e61e, 5.10.227, 6.10.14, 5.15.168, 2.6.27, <=6.10.*, <e6897e299f57b103e999e62010b88e363b3eebae) est présent sur votre parc.
• Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
• À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
• Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.

Références

• https://git.kernel.org/stable/c/e657fa2df4429f3805a9b3e47fb1a4a1b02a72bd
• https://git.kernel.org/stable/c/6d0a07f68b66269e167def6c0b90a219cd3e7473
• https://git.kernel.org/stable/c/e6897e299f57b103e999e62010b88e363b3eebae
• https://git.kernel.org/stable/c/4cda484e584be34d55ee17436ebf7ad11922b97a
• https://git.kernel.org/stable/c/3c0d416eb4bef705f699213cee94bf54b6acdacd
• https://git.kernel.org/stable/c/fdda354f60a576d52dcf90351254714681df4370
• https://git.kernel.org/stable/c/aaadc0cb05c999ccd8898a03298b7e5c31509b08
• https://git.kernel.org/stable/c/a3a855764dbacbdb1cc51e15dc588f2d21c93e0e
• https://git.kernel.org/stable/c/4a6921095eb04a900e0000da83d9475eb958e61e