CVE-2023-53458

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> media: cx23885: Fix a null-ptr-deref bug in buffer_prepare() and buffer_finish()<br /> <br /> When the driver calls cx23885_risc_buffer() to prepare the buffer, the<br /> function call dma_alloc_coherent may fail, resulting in a empty buffer<br /> risc-&gt;cpu. Later when we free the buffer or access the buffer, null ptr<br /> deref is triggered.<br /> <br /> This bug is similar to the following one:<br /> https://git.linuxtv.org/media_stage.git/commit/?id=2b064d91440b33fba5b452f2d1b31f13ae911d71.<br /> <br /> We believe the bug can be also dynamically triggered from user side.<br /> Similarly, we fix this by checking the return value of cx23885_risc_buffer()<br /> and the value of risc-&gt;cpu before buffer free.