CVE-2025-40060

In the Linux kernel, the following vulnerability has been resolved:

coresight: trbe: Return NULL pointer for allocation failures

When the TRBE driver fails to allocate a buffer, it currently returns
the error code "-ENOMEM". However, the caller etm_setup_aux() only
checks for a NULL pointer, so it misses the error. As a result, the
driver continues and eventually causes a kernel panic.

Fix this by returning a NULL pointer from arm_trbe_alloc_buffer() on
allocation failures. This allows that the callers can properly handle
the failure.