[ Upstream commit 0f5bb36bf9b39a2a96e730bf4455095b50713f63 ] When Universal DVB card is detaching, netup_unidvb_dma_fini() uses del_timer() to stop dma->timeout timer. But when timer handler netup_unidvb_dma_timeout() is running, del_timer() could not stop it. As a result, the use-after-free bug could happen. The process is shown below: (cleanup routine) | (timer routine) | mod_timer(&dev->tx_sim_timer, ..) netup_unidvb_finidev() | (wait a time) netup_unidvb_dma_fini() | netup_unidvb_dma_timeout() del_timer(&dma->timeout); | | ndev->pci_dev->dev //USE Fix by changing del_timer() to del_timer_sync(). Link: https://lore.kernel.org/linux-media/20230308125514.4208-1-duoming@zju.edu.cn Fixes: 52b1eaf4c59a ("[media] netup_unidvb: NetUP Universal DVB-S/S2/T/T2/C PCI-E card driver") Signed-off-by: Duoming Zhou <duoming@zju.edu.cn> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ There are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. Please read Documentation/admin-guide/README.rst first. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. The formatted documentation can also be read online at: https://www.kernel.org/doc/html/latest/ There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. Please read the Documentation/process/changes.rst file, as it contains the requirements for building and running the kernel, and information about the problems which may result by upgrading your kernel.
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