UPSTREAM: memstick: r592: Fix UAF bug in r592_remove due to race condition
[ Upstream commit 63264422785021704c39b38f65a78ab9e4a186d7 ]
In r592_probe, dev->detect_timer was bound with r592_detect_timer.
In r592_irq function, the timer function will be invoked by mod_timer.
If we remove the module which will call hantro_release to make cleanup,
there may be a unfinished work. The possible sequence is as follows,
which will cause a typical UAF bug.
Fix it by canceling the work before cleanup in r592_remove.
CPU0 CPU1
|r592_detect_timer
r592_remove |
memstick_free_host|
put_device; |
kfree(host); |
|
| queue_work
| &host->media_checker //use
Bug: 287729043
Signed-off-by: Zheng Wang <zyytlz.wz@163.com>
Link: https://lore.kernel.org/r/20230307164338.1246287-1-zyytlz.wz@163.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 9a342d4eb9fb8e52f7d1afe088a79513f3f9a9a5)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: Idb15f593287ebaeec294b3e276126306fa6743ba
diff --git a/drivers/memstick/host/r592.c b/drivers/memstick/host/r592.c
index eaa2a94..dd06c18 100644
--- a/drivers/memstick/host/r592.c
+++ b/drivers/memstick/host/r592.c
@@ -828,7 +828,7 @@
/* Stop the processing thread.
That ensures that we won't take any more requests */
kthread_stop(dev->io_thread);
-
+ del_timer_sync(&dev->detect_timer);
r592_enable_device(dev, false);
while (!error && dev->req) {
