orangefs: Avoid symlink upcall if target is too long.

Previously the client-core detected this condition by sheer luck!

Since we used strncpy, no NUL byte would be included on the name. The
client-core would call strlen, which would read past the end of its
buffer, but return a number large enough that the client-core would
return ENAMETOOLONG.

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/fs/orangefs/namei.c b/fs/orangefs/namei.c
index 650ff299738b..5a60c508af4e 100644
--- a/fs/orangefs/namei.c
+++ b/fs/orangefs/namei.c
@@ -269,6 +269,9 @@ static int orangefs_symlink(struct inode *dir,
         if (!symname)
                 return -EINVAL;
 
+        if (strlen(symname)+1 > ORANGEFS_NAME_MAX)
+                return -ENAMETOOLONG;
+
         new_op = op_alloc(ORANGEFS_VFS_OP_SYMLINK);
         if (!new_op)
                 return -ENOMEM;