xfs: fix potential memory leak in mount option parsing

When specifying string type mount option (e.g., logdev)
several times in a mount, current option parsing may
cause memory leak. Hence, call kfree for previous one
in this case.

Signed-off-by: Chengguang Xu <cgxu519@icloud.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

diff --git a/fs/xfs/xfs_super.c b/fs/xfs/xfs_super.c
index 7aba628..93588ea 100644 (file)
--- a/fs/xfs/xfs_super.c
+++ b/fs/xfs/xfs_super.c
@@ -250,6 +250,7 @@ xfs_parseargs(
                                return -EINVAL;
                        break;
                case Opt_logdev:
+                       kfree(mp->m_logname);
                        mp->m_logname = match_strdup(args);
                        if (!mp->m_logname)
                                return -ENOMEM;
@@ -258,6 +259,7 @@ xfs_parseargs(
                        xfs_warn(mp, "%s option not allowed on this system", p);
                        return -EINVAL;
                case Opt_rtdev:
+                       kfree(mp->m_rtname);
                        mp->m_rtname = match_strdup(args);
                        if (!mp->m_rtname)
                                return -ENOMEM;