An attempt to open a file with a name longer than NFS3_MAXNAMLEN will trigger a WARN_ON_ONCE in encode_filename3() because nfs_atomic_open_v23() doesn't have the test on ->d_name.len that nfs_atomic_open() has. So add that test. Reported-by: James Clark <james.clark@xxxxxxx> Closes: https://lore.kernel.org/all/20240528105249.69200-1-james.clark@xxxxxxx/ Fixes: 7c6c5249f061 ("NFS: add atomic_open for NFSv3 to handle O_TRUNC correctly.") Signed-off-by: NeilBrown <neilb@xxxxxxx> --- fs/nfs/dir.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 342930996226..2b09b5416ef1 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2255,6 +2255,9 @@ int nfs_atomic_open_v23(struct inode *dir, struct dentry *dentry, */ int error = 0; + if (dentry->d_name.len > NFS_SERVER(dir)->namelen) + return -ENAMETOOLONG; + if (open_flags & O_CREAT) { file->f_mode |= FMODE_CREATED; error = nfs_do_create(dir, dentry, mode, open_flags); -- 2.44.0
