CVE-2022-50819 — NULL Pointer Dereference in Linux

In the Linux kernel, the following vulnerability has been resolved: udmabuf: Set ubuf->sg = NULL if the creation of sg table fails When userspace tries to map the dmabuf and if for some reason (e.g. OOM) the creation of the sg table fails, ubuf->sg needs to be set to NULL. Otherwise, when the userspace subsequently closes the dmabuf fd, we'd try to erroneously free the invalid sg table from release_udmabuf resulting in the following crash reported by syzbot: general protection fault, probably…