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memstick: r592: Fix UAF bug in r592_remove due to race condition

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[ 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

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>
This commit is contained in:
Zheng Wang 2023-03-08 00:43:38 +08:00 committed by Greg Kroah-Hartman
parent d73e8c4767
commit a2a5d3a584
1 changed files with 1 additions and 1 deletions
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2
drivers/memstick/host/r592.c
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@ -828,7 +828,7 @@ static void r592_remove(struct pci_dev *pdev)
/* 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) {