NFS: abort nfs_atomic_open_v23 if name is too long.

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 <[email protected]> Closes: https://lore.kernel.org/all/[email protected]/ Fixes: 7c6c524 ("NFS: add atomic_open for NFSv3 to handle O_TRUNC correctly.") Signed-off-by: NeilBrown <[email protected]> Reviewed-by: Christoph Hellwig <[email protected]> Signed-off-by: Trond Myklebust <[email protected]>
torvalds · May 30, 2024 · 296f4ce · 296f4ce
1 parent 0c8c7c5
commit 296f4ce
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c
@@ -2254,6 +2254,9 @@ 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);