Vulnerability CVE-2023-52847
Published: 2024-05-21

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

media: bttv: fix use after free error due to btv->timeout timer

There may be some a race condition between timer function
bttv_irq_timeout and bttv_remove. The timer is setup in
probe and there is no timer_delete operation in remove
function. When it hit kfree btv, the function might still be
invoked, which will cause use after free bug.

This bug is found by static analysis, it may be false positive.

Fix it by adding del_timer_sync invoking to the remove function.

cpu0 cpu1
bttv_probe
->timer_setup
->bttv_set_dma
->mod_timer;
bttv_remove
->kfree(btv);
->bttv_irq_timeout
->USE btv

 References:
https://git.kernel.org/stable/c/bbc3b8dd2cb7817e703f112d988e4f4728f0f2a9
https://git.kernel.org/stable/c/b35fdade92c5058a5e727e233fe263b828de2c9a
https://git.kernel.org/stable/c/2f3d9198cdae1cb079ec8652f4defacd481eab2b
https://git.kernel.org/stable/c/51c94256a83fe4e17406c66ff3e1ad7d242d8574
https://git.kernel.org/stable/c/20568d06f6069cb835e05eed432edf962645d226
https://git.kernel.org/stable/c/1871014d6ef4812ad11ef7d838d73ce09d632267
https://git.kernel.org/stable/c/847599fffa528b2cdec4e21b6bf7586dad982132
https://git.kernel.org/stable/c/bd5b50b329e850d467e7bcc07b2b6bde3752fbda
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