ovl: fix NULL pointer defer when encoding non-decodable lower fid

A wrong return value from ovl_check_encode_origin() would cause ovl_dentry_to_fid() to try to encode fid from NULL upper dentry. Reported-by: [email protected] Fixes: 16aac5a ("ovl: support encoding non-decodable file handles") Signed-off-by: Amir Goldstein <[email protected]>
kawasaki · Oct 3, 2023 · c7242a4 · c7242a4
1 parent a535116
commit c7242a4
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/fs/overlayfs/export.c b/fs/overlayfs/export.c
@@ -188,7 +188,7 @@ static int ovl_check_encode_origin(struct dentry *dentry)
 
 	/* Lower file handle for non-upper non-decodable */
 	if (!ovl_dentry_upper(dentry) && !decodable)
-		return 0;
+		return 1;
 
 	/* Upper file handle for pure upper */
 	if (!ovl_dentry_lower(dentry))