6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Chuck Lever <chuck.lever@xxxxxxxxxx>
commit 42c3732fa8073717dd7d924472f1c0bc5b452fdc upstream.
De-duplicate the same functionality in several places by hoisting
the is_dot_dotdot() utility function into linux/fs.h.
Suggested-by: Amir Goldstein <amir73il@xxxxxxxxx>
Reviewed-by: Jeff Layton <jlayton@xxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Acked-by: Christian Brauner <brauner@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/crypto/fname.c | 8 +-------
fs/ecryptfs/crypto.c | 10 ----------
fs/f2fs/f2fs.h | 11 -----------
fs/namei.c | 6 ++----
include/linux/fs.h | 11 +++++++++++
5 files changed, 14 insertions(+), 32 deletions(-)
--- a/fs/crypto/fname.c
+++ b/fs/crypto/fname.c
@@ -74,13 +74,7 @@ struct fscrypt_nokey_name {
static inline bool fscrypt_is_dot_dotdot(const struct qstr *str)
{
- if (str->len == 1 && str->name[0] == '.')
- return true;
-
- if (str->len == 2 && str->name[0] == '.' && str->name[1] == '.')
- return true;
-
- return false;
+ return is_dot_dotdot(str->name, str->len);
}
/**
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1973,16 +1973,6 @@ out:
return rc;
}
-static bool is_dot_dotdot(const char *name, size_t name_size)
-{
- if (name_size == 1 && name[0] == '.')
- return true;
- else if (name_size == 2 && name[0] == '.' && name[1] == '.')
- return true;
-
- return false;
-}
-
/**
* ecryptfs_decode_and_decrypt_filename - converts the encoded cipher text name to decoded plaintext
* @plaintext_name: The plaintext name
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -3335,17 +3335,6 @@ static inline bool f2fs_cp_error(struct
return is_set_ckpt_flags(sbi, CP_ERROR_FLAG);
}
-static inline bool is_dot_dotdot(const u8 *name, size_t len)
-{
- if (len == 1 && name[0] == '.')
- return true;
-
- if (len == 2 && name[0] == '.' && name[1] == '.')
- return true;
-
- return false;
-}
-
static inline void *f2fs_kmalloc(struct f2fs_sb_info *sbi,
size_t size, gfp_t flags)
{
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2663,10 +2663,8 @@ static int lookup_one_common(struct user
if (!len)
return -EACCES;
- if (unlikely(name[0] == '.')) {
- if (len < 2 || (len == 2 && name[1] == '.'))
- return -EACCES;
- }
+ if (is_dot_dotdot(name, len))
+ return -EACCES;
while (len--) {
unsigned int c = *(const unsigned char *)name++;
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3107,6 +3107,17 @@ extern bool path_is_under(const struct p
extern char *file_path(struct file *, char *, int);
+/**
+ * is_dot_dotdot - returns true only if @name is "." or ".."
+ * @name: file name to check
+ * @len: length of file name, in bytes
+ */
+static inline bool is_dot_dotdot(const char *name, size_t len)
+{
+ return len && unlikely(name[0] == '.') &&
+ (len == 1 || (len == 2 && name[1] == '.'));
+}
+
#include <linux/err.h>
/* needed for stackable file system support */
