CVE-2024-49924

Summary

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.

Affected Software

VendorProductVersion RangeStatus
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < e657fa2df4429f3805a9b3e47fb1a4a1b02a72bdaffected
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < 6d0a07f68b66269e167def6c0b90a219cd3e7473affected
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < e6897e299f57b103e999e62010b88e363b3eebaeaffected
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < 4cda484e584be34d55ee17436ebf7ad11922b97aaffected
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < 3c0d416eb4bef705f699213cee94bf54b6acdacdaffected
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < fdda354f60a576d52dcf90351254714681df4370affected
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < aaadc0cb05c999ccd8898a03298b7e5c31509b08affected
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < a3a855764dbacbdb1cc51e15dc588f2d21c93e0eaffected
LinuxLinux9f17f2874834f4cdbe48cc05676d8f7558793204 < 4a6921095eb04a900e0000da83d9475eb958e61eaffected
LinuxLinux2.6.27affected
LinuxLinux0 < 2.6.27unaffected
LinuxLinux4.19.323 <= 4.19.*unaffected
LinuxLinux5.4.285 <= 5.4.*unaffected
LinuxLinux5.10.227 <= 5.10.*unaffected
LinuxLinux5.15.168 <= 5.15.*unaffected
LinuxLinux6.1.113 <= 6.1.*unaffected
LinuxLinux6.6.55 <= 6.6.*unaffected
LinuxLinux6.10.14 <= 6.10.*unaffected
LinuxLinux6.11.3 <= 6.11.*unaffected
LinuxLinux6.12 <= *unaffected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: partial

CVE Program Container

Additional References

References