CVE-2026-53315

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

drm/amd/ras: Fix NULL deref in rascoregetutcsecond_timestamp()

rascoregetutcsecond_timestamp() retrieves the current UTC timestamp (in seconds since the Unix epoch) through a platform-specific RAS system callback and is used for timestamping RAS error events.

The function checks rascore in the conditional statement before calling the sysfn callback. However, when the condition fails, the function prints an error message using ras_core->dev.

If rascore is NULL, this can lead to a potential NULL pointer dereference when accessing rascore->dev.

Add an early NULL check for ras_core at the beginning of the function and return 0 when the pointer is not valid. This prevents the dereference and makes the control flow clearer.