CVE-2025-68776 net/hsr: fix NULL pointer dereference in prp_get_untagged_frame()

In the Linux kernel, the following vulnerability has been resolved: net/hsr: fix NULL pointer dereference in prpgetuntaggedframe prpgetuntaggedframe calls pskbcopy to create frame-skbstd but doesn't check if the allocation failed. If pskbcopy returns NULL, skbclone is called with a NULL pointer,...