tjh.dev / kernel
Linux kernel mirror (for testing) git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel os linux
1
fork

Configure Feed

Select the types of activity you want to include in your feed.

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

Fixes: 162e6376ac58 ("media: pci: Convert timers to use timer_setup()")
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>

authored by

Zheng Wang and committed by
Hans Verkuil bd5b50b3 56e9e480

+1
+1
drivers/media/pci/bt8xx/bttv-driver.c
··· 3474 3474 3475 3475 /* free resources */ 3476 3476 free_irq(btv->c.pci->irq,btv); 3477 + del_timer_sync(&btv->timeout); 3477 3478 iounmap(btv->bt848_mmio); 3478 3479 release_mem_region(pci_resource_start(btv->c.pci,0), 3479 3480 pci_resource_len(btv->c.pci,0));