Vulnerability in Linux

[ Description ]Official description

In the Linux kernel, the following vulnerability has been resolved: mmc: mtk-sd: Cancel request timeout work on remove The driver queues req_timeout while a request is active. msdc_request_done() uses cancel_delayed_work(), which does not wait for a timeout callback that has already started. The timeout callback calls mmc_request_done(), which wakes the request waiter, and then continues to use host->dev_comp and check the SDIO IRQ. During unbind, msdc_drv_remove() can return and the managed mmc_host can be freed before the callback finishes. KASAN reported use-after-free accesses in msdc_request_done() and msdc_recheck_sdio_irq() in each of three unbind tests. The same tests completed without a kernel diagnostic after this change. Call cancel_delayed_work_sync() after mmc_remove_host() has stopped new requests and before the driver releases the host resources.

[ Fixes ]Fixes and patches

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References

• git.kernel.org/stable/c/46e75703ca3f00fb8c935b3ce35b90836e34e8af
• git.kernel.org/stable/c/9e799f25c420e759641eb25102967ea091fc758f
• git.kernel.org/stable/c/b38af5386a74416e898955443f2e26547b358cb2
• git.kernel.org/stable/c/edef1355224c0799a502a46b71d3649fa0dd218e
• git.kernel.org/stable/c/f37e0367ad6f2147a0b37564b442b7a25bec0d23