memstick: r592: Fix UAF bug in r592_remove due to race condition
Bugzilla: https://bugzilla.redhat.com/2215907
CVE: CVE-2023-35825
commit 63264422785021704c39b38f65a78ab9e4a186d7
Author: Zheng Wang zyytlz.wz@163.com
Date: Wed Mar 8 00:43:38 2023 +0800
memstick: r592: Fix UAF bug in r592_remove due to race condition
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
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: Wander Lairson Costa wander@redhat.com
Edited by Wander Lairson Costa