ext3: fix a bug accessing freed memory in ext3_abort

Vegard Nossum reported a bug which accesses freed memory (found via
kmemcheck).  When journal has been aborted, ext3_put_super() calls
ext3_abort() after freeing the journal_t object, and then ext3_abort()
accesses it.  This patch fix it.

Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Acked-by: Jan Kara <jack@suse.cz>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 7 insertions, 3 deletions

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 18eaa78ecb4e..e5717a4fae67 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -281,7 +281,8 @@ void ext3_abort (struct super_block * sb, const char * function,
         EXT3_SB(sb)->s_mount_state |= EXT3_ERROR_FS;
         sb->s_flags |= MS_RDONLY;
         EXT3_SB(sb)->s_mount_opt |= EXT3_MOUNT_ABORT;
-        journal_abort(EXT3_SB(sb)->s_journal, -EIO);
+        if (EXT3_SB(sb)->s_journal)
+                journal_abort(EXT3_SB(sb)->s_journal, -EIO);
 }
 
 void ext3_warning (struct super_block * sb, const char * function,
@@ -390,11 +391,14 @@ static void ext3_put_super (struct super_block * sb)
 {
         struct ext3_sb_info *sbi = EXT3_SB(sb);
         struct ext3_super_block *es = sbi->s_es;
-        int i;
+        int i, err;
 
         ext3_xattr_put_super(sb);
-        if (journal_destroy(sbi->s_journal) < 0)
+        err = journal_destroy(sbi->s_journal);
+        sbi->s_journal = NULL;
+        if (err < 0)
                 ext3_abort(sb, __func__, "Couldn't clean up the journal");
+
         if (!(sb->s_flags & MS_RDONLY)) {
                 EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
                 es->s_state = cpu_to_le16(sbi->s_mount_state);