[PATCH 4.5 162/200] f2fs crypto: fix corrupted symlink in encrypted case

Greg Kroah-Hartman
2016-05-03T00:47:18Z

From: Jaegeuk Kim <jaegeuk@kernel.org>

commit c90e09f7fb498f81cd4e8bb6460d3a26ccebeca3 upstream.

In the encrypted symlink case, we should check its corrupted symname after
decrypting it.
Otherwise, we can report -ENOENT incorrectly, if encrypted symname starts with
'\0'.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/f2fs/namei.c | 12 ++++++------
1 file changed, 6 insertions(+), 6 deletions(-)

--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -980,12 +980,6 @@ static const char *f2fs_encrypted_get_li
}
memcpy(cstr.name, sd->encrypted_path, cstr.len);

- /* this is broken symlink case */
- if (unlikely(cstr.name[0] == 0)) {
- res = -ENOENT;
- goto errout;
- }
-
if ((cstr.len + sizeof(struct f2fs_encrypted_symlink_data) - 1) >
max_size) {
/* Symlink data on the disk is corrupted */
@@ -1002,6 +996,12 @@ static const char *f2fs_encrypted_get_li

kfree(cstr.name);

+ /* this is broken symlink case */
+ if (unlikely(pstr.name[0] == 0)) {
+ res = -ENOENT;
+ goto errout;
+ }
+
paddr = pstr.name;

/* Null-terminate the name */