From: Zheng Wang zyytlz.wz@163.com

mainline inclusion from mainline-v6.7-rc1 commit bd5b50b329e850d467e7bcc07b2b6bde3752fbda category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9RFON CVE: CVE-2023-52847

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...

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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 Signed-off-by: Ye Bin yebin10@huawei.com --- drivers/media/pci/bt8xx/bttv-driver.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/media/pci/bt8xx/bttv-driver.c b/drivers/media/pci/bt8xx/bttv-driver.c index cf05e11da01b..00400f58d9c4 100644 --- a/drivers/media/pci/bt8xx/bttv-driver.c +++ b/drivers/media/pci/bt8xx/bttv-driver.c @@ -4293,6 +4293,7 @@ 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));