[PATCH 11/21] namei: make filename_lookup() reject ERR_PTR() passed as name

From: Al Viro
Date: Wed May 13 2015 - 18:31:46 EST


From: Al Viro <viro@xxxxxxxxxxxxxxxxxx>

makes for much easier life in callers

Signed-off-by: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
---
fs/namei.c | 30 ++++++++++--------------------
1 file changed, 10 insertions(+), 20 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index abf65b0..6607a05 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2120,7 +2120,10 @@ static int filename_lookup(int dfd, struct filename *name, unsigned flags,
struct path *path, struct path *root)
{
int retval;
- struct nameidata nd, *saved_nd = set_nameidata(&nd);
+ struct nameidata nd, *saved_nd;
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+ saved_nd = set_nameidata(&nd);
if (unlikely(root)) {
nd.root = *root;
flags |= LOOKUP_ROOT;
@@ -2210,10 +2213,8 @@ out:

int kern_path(const char *name, unsigned int flags, struct path *path)
{
- struct filename *filename = getname_kernel(name);
- if (IS_ERR(filename))
- return PTR_ERR(filename);
- return filename_lookup(AT_FDCWD, filename, flags, path, NULL);
+ return filename_lookup(AT_FDCWD, getname_kernel(name),
+ flags, path, NULL);
}
EXPORT_SYMBOL(kern_path);

@@ -2230,15 +2231,9 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt,
struct path *path)
{
struct path root = {.mnt = mnt, .dentry = dentry};
- struct filename *filename = getname_kernel(name);
-
- BUG_ON(flags & LOOKUP_PARENT);
-
- if (IS_ERR(filename))
- return PTR_ERR(filename);
-
/* the first argument of filename_lookup() is ignored with root */
- return filename_lookup(AT_FDCWD, filename, flags , path, &root);
+ return filename_lookup(AT_FDCWD, getname_kernel(name),
+ flags , path, &root);
}
EXPORT_SYMBOL(vfs_path_lookup);

@@ -2296,13 +2291,8 @@ EXPORT_SYMBOL(lookup_one_len);
int user_path_at_empty(int dfd, const char __user *name, unsigned flags,
struct path *path, int *empty)
{
- struct filename *tmp = getname_flags(name, flags, empty);
- if (IS_ERR(tmp))
- return PTR_ERR(tmp);
-
- BUG_ON(flags & LOOKUP_PARENT);
-
- return filename_lookup(dfd, tmp, flags, path, NULL);
+ return filename_lookup(dfd, getname_flags(name, flags, empty),
+ flags, path, NULL);
}

int user_path_at(int dfd, const char __user *name, unsigned flags,
--
2.1.4

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