From 203c792cb4315360d49973ae2e57feeb6d3dcf7e Mon Sep 17 00:00:00 2001 From: Roberto Bergantinos Corpas Date: Thu, 19 Feb 2026 13:04:40 +0100 Subject: nfs: return EISDIR on nfs3_proc_create if d_alias is a dir [ Upstream commit 410666a298c34ebd57256fde6b24c96bd23059a2 ] If we found an alias through nfs3_do_create/nfs_add_or_obtain /d_splice_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 nfs_atomic_open_v23/finish_open since we supply a negative dentry to do_dentry_open. 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 d_splice_alias typically returns a directory alias or NULL, we explicitly check d_is_dir() to ensure that we don't attempt to perform file operations (like finish_open) on a directory inode, which triggers the observed oops. Fixes: 7c6c5249f061 ("NFS: add atomic_open for NFSv3 to handle O_TRUNC correctly.") Reviewed-by: Olga Kornievskaia Reviewed-by: Scott Mayhew Signed-off-by: Roberto Bergantinos Corpas Signed-off-by: Anna Schumaker Signed-off-by: Sasha Levin --- fs/nfs/nfs3proc.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/fs/nfs/nfs3proc.c b/fs/nfs/nfs3proc.c index a4cb67573aa7..993f62636a77 100644 --- a/fs/nfs/nfs3proc.c +++ b/fs/nfs/nfs3proc.c @@ -392,8 +392,13 @@ nfs3_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr, if (status != 0) goto out_release_acls; - if (d_alias) + if (d_alias) { + if (d_is_dir(d_alias)) { + status = -EISDIR; + goto out_dput; + } dentry = d_alias; + } /* When we created the file with exclusive semantics, make * sure we set the attributes afterwards. */ -- cgit v1.2.3