In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: Fix a possible null-pointer dereference in niclear() In a previous commit c1006bd13146, ni->mi.mrec in niwriteinode() could be NULL, and thus a NULL check is added for this variable. However, in the same call stack, ni->mi.mrec can be also dereferenced in niclear(): ntfsevictinode(inode) niwriteinode(inode, ...) ni = ntfsi(inode); isrecinuse(ni->mi.mrec) -> Add a NULL check by previous commit niclear(ntfsi(inode)) isrecinuse(ni->mi.mrec) -> No check Thus, a possible null-pointer dereference may exist in niclear(). To fix it, a NULL check is added in this function.