[PATCH] HFS: fix memory leak when unmounting

[Dave Anderson]

When an HFS filesystem is unmounted, it leaks a 2-page
bitmap.  Also, under extreme memory pressure, it's possible
that hfs_releasepage() may use a tree pointer that has not
been initialized, and if so, the release request should
just be rejected.

Signed-off-by: Dave Anderson <anderson@xxxxxxxxxx>






diff --git a/fs/hfs/inode.c b/fs/hfs/inode.c
index 9435dda..a1cbff2 100644
--- a/fs/hfs/inode.c
+++ b/fs/hfs/inode.c
@@ -70,6 +70,10 @@ static int hfs_releasepage(struct page *page, gfp_t mask)
 		BUG();
 		return 0;
 	}
+
+	if (!tree)
+		return 0;
+
 	if (tree->node_size >= PAGE_CACHE_SIZE) {
 		nidx = page->index >> (tree->node_size_shift - PAGE_CACHE_SHIFT);
 		spin_lock(&tree->hash_lock);
diff --git a/fs/hfs/mdb.c b/fs/hfs/mdb.c
index 36ca2e1..369f2af 100644
--- a/fs/hfs/mdb.c
+++ b/fs/hfs/mdb.c
@@ -349,6 +349,10 @@ void hfs_mdb_put(struct super_block *sb)
 	if (HFS_SB(sb)->nls_disk)
 		unload_nls(HFS_SB(sb)->nls_disk);
 
+	/* free the bitmap page(s) */
+	if (HFS_SB(sb)->bitmap)
+		free_pages((unsigned long)HFS_SB(sb)->bitmap, PAGE_SIZE < 8192 ? 1 : 0);
+
 	kfree(HFS_SB(sb));
 	sb->s_fs_info = NULL;
 }