Patchwork [7/7] UBIFS: fix a rare memory leak in ro to rw remounting path

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Submitter Artem Bityutskiy
Date May 6, 2011, 2:15 p.m.
Message ID <1304691317-32214-7-git-send-email-dedekind1@gmail.com>
Download mbox | patch
Permalink /patch/94390/
State Accepted
Commit eaeee242c531cd4b0a4a46e8b5dd7ef504380c42
Headers show

Comments

Artem Bityutskiy - May 6, 2011, 2:15 p.m.
From: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

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@nokia.com>
Cc: stable@kernel.org
---
 fs/ubifs/sb.c    |    3 ++-
 fs/ubifs/super.c |    1 +
 2 files changed, 3 insertions(+), 1 deletions(-)

Patch

diff --git a/fs/ubifs/sb.c b/fs/ubifs/sb.c
index bf31b47..cad60b5 100644
--- a/fs/ubifs/sb.c
+++ b/fs/ubifs/sb.c
@@ -475,7 +475,8 @@  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)
 {
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 407c064..575ea83 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -1585,6 +1585,7 @@  static int ubifs_remount_rw(struct ubifs_info *c)
 		}
 		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
 		err = ubifs_write_sb_node(c, sup);
+		kfree(sup);
 		if (err)
 			goto out;
 	}