[37/85] UBIFS: fix a rare memory leak in ro to rw remounting path

From: Greg KH
Date: Thu Jun 16 2011 - 03:18:09 EST

2.6.33-longterm review patch. If anyone has any objections, please let us know.


From: Artem Bityutskiy <Artem.Bityutskiy@xxxxxxxxx>

commit eaeee242c531cd4b0a4a46e8b5dd7ef504380c42 upstream.

When re-mounting from R/O mode to R/W mode and the LEB count in the superblock
is not up-to date, because for the underlying UBI volume became larger, we
re-write the superblock. We allocate RAM for these purposes, but never free it.
So this is a memory leak, although very rare one.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>

fs/ubifs/sb.c | 3 ++-
fs/ubifs/super.c | 1 +
2 files changed, 3 insertions(+), 1 deletion(-)

--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -474,7 +474,8 @@ failed:
* @c: UBIFS file-system description object
* This function returns a pointer to the superblock node or a negative error
- * code.
+ * code. Note, the user of this function is responsible of kfree()'ing the
+ * returned superblock buffer.
struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1545,6 +1545,7 @@ static int ubifs_remount_rw(struct ubifs
sup->leb_cnt = cpu_to_le32(c->leb_cnt);
err = ubifs_write_sb_node(c, sup);
+ kfree(sup);
if (err)
goto out;

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