orangefs: Fix the size of a memory allocation in orangefs_bufmap_alloc()

BugLink: https://bugs.launchpad.net/bugs/1958977
commit 40a74870b2d1d3d44e13b3b73c6571dd34f5614d upstream.

'buffer_index_array' really looks like a bitmap. So it should be allocated
as such.
When kzalloc is called, a number of bytes is expected, but a number of
longs is passed instead.

In get(), if not enough memory is allocated, un-allocated memory may be
read or written.

So use bitmap_zalloc() to safely allocate the correct memory size and
avoid un-expected behavior.

While at it, change the corresponding kfree() into bitmap_free() to keep
the semantic.

Fixes: ea2c9c9f6574 ("orangefs: bufmap rewrite")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/fs/orangefs/orangefs-bufmap.c b/fs/orangefs/orangefs-bufmap.c
index 538e839590ef5c1d489aea7f6d94a7e9d1be821b..b501dc07f92224474f2cf1a27194e492429a019f 100644 (file)
--- a/fs/orangefs/orangefs-bufmap.c
+++ b/fs/orangefs/orangefs-bufmap.c
@@ -176,7 +176,7 @@ orangefs_bufmap_free(struct orangefs_bufmap *bufmap)
 {
        kfree(bufmap->page_array);
        kfree(bufmap->desc_array);
-       kfree(bufmap->buffer_index_array);
+       bitmap_free(bufmap->buffer_index_array);
        kfree(bufmap);
 }
 
@@ -226,8 +226,7 @@ orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc)
        bufmap->desc_size = user_desc->size;
        bufmap->desc_shift = ilog2(bufmap->desc_size);
 
-       bufmap->buffer_index_array =
-               kzalloc(DIV_ROUND_UP(bufmap->desc_count, BITS_PER_LONG), GFP_KERNEL);
+       bufmap->buffer_index_array = bitmap_zalloc(bufmap->desc_count, GFP_KERNEL);
        if (!bufmap->buffer_index_array)
                goto out_free_bufmap;
 
@@ -250,7 +249,7 @@ orangefs_bufmap_alloc(struct ORANGEFS_dev_map_desc *user_desc)
 out_free_desc_array:
        kfree(bufmap->desc_array);
 out_free_index_array:
-       kfree(bufmap->buffer_index_array);
+       bitmap_free(bufmap->buffer_index_array);
 out_free_bufmap:
        kfree(bufmap);
 out: