| Message ID | 20230413034405.36037-1-zyytlz.wz@163.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [RESEND,v2] media: bttv: fix use after free error due to btv->timeout timer | expand |
diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c index d40b537f4e98..24ba5729969d 100644 --- a/drivers/media/pci/bt8xx/bttv-driver.c +++ b/drivers/media/pci/bt8xx/bttv-driver.c @@ -4248,6 +4248,7 @@ static void bttv_remove(struct pci_dev *pci_dev) /* free resources */ free_irq(btv->c.pci->irq,btv); + del_timer_sync(&btv->timeout); iounmap(btv->bt848_mmio); release_mem_region(pci_resource_start(btv->c.pci,0), pci_resource_len(btv->c.pci,0));
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 Signed-off-by: Zheng Wang <zyytlz.wz@163.com> --- v2: - stop replacing del_timer with del_timer_sync suggested by Hillf Danton --- drivers/media/pci/bt8xx/bttv-driver.c | 1 + 1 file changed, 1 insertion(+)