From: Duoming Zhou duoming@zju.edu.cn
commit 3f4093e2bf4673f218c0bf17d8362337c400e77b upstream.
There are use-after-free bugs caused by tst_timer. The root cause is that there are no functions to stop tst_timer in idt77252_exit(). One of the possible race conditions is shown below:
(thread 1) | (thread 2) | idt77252_init_one | init_card | fill_tst | mod_timer(&card->tst_timer, ...) idt77252_exit | (wait a time) | tst_timer | | ... kfree(card) // FREE | | card->soft_tst[e] // USE
The idt77252_dev is deallocated in idt77252_exit() and used in timer handler.
This patch adds del_timer_sync() in idt77252_exit() in order that the timer handler could be stopped before the idt77252_dev is deallocated.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Duoming Zhou duoming@zju.edu.cn Link: https://lore.kernel.org/r/20220805070008.18007-1-duoming@zju.edu.cn Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/atm/idt77252.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/atm/idt77252.c +++ b/drivers/atm/idt77252.c @@ -3768,6 +3768,7 @@ static void __exit idt77252_exit(void) card = idt77252_chain; dev = card->atmdev; idt77252_chain = card->next; + del_timer_sync(&card->tst_timer);
if (dev->phy->stop) dev->phy->stop(dev);