CVE-2026-43470

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

nfs: return EISDIR on nfs3proccreate if d_alias is a dir

If we found an alias through nfs3docreate/nfsaddorobtain /dsplice_alias which happens to be a dir dentry, we don't return any error, and simply forget about this alias, but the original dentry we were adding and passed as parameter remains negative.

This later causes an oops on nfsatomicopenv23/finishopen since we supply a negative dentry to dodentryopen.

This has been observed running lustre-racer, where dirs and files are created/removed concurrently with the same name and O_EXCL is not used to open files (frequent file redirection).

While dsplicealias typically returns a directory alias or NULL, we explicitly check disdir() to ensure that we don't attempt to perform file operations (like finish_open) on a directory inode, which triggers the observed oops.