Linux Kernel DMA Engine Null Pointer Dereference Vulnerability in AT XDMAC Component

A null pointer dereference vulnerability has been identified in the Linux kernel's DMA engine, specifically within the AT XDMAC component. The issue arises in the 'at_xdmac_memset_create_desc' function, which may return a NULL value. This can lead to a null pointer dereference if, for instance, the 'len' input is erroneous, or if the 'atchan->free_descs_list' is empty and memory resources are depleted. The vulnerability has been addressed by adding a check to prevent the null pointer dereference.

Impact

Exploitation of this vulnerability can lead to a null pointer dereference, causing a kernel crash.