From: John Pittman <jpittman@xxxxxxxxxx>
commit 45422b704db392a6d79d07ee3e3670b11048bd53 upstream.
Due to unneeded multiplication in the out_free_pages portion of
r10buf_pool_alloc(), when using a 3-copy raid10 layout, it is
possible to access a resync_pages offset that has not been
initialized. This access translates into a crash of the system
within resync_free_pages() while passing a bad pointer to
put_page(). Remove the multiplication, preventing access to the
uninitialized area.
Fixes: f0250618361db ("md: raid10: don't use bio's vec table to manage resync pages")
Cc: stable@xxxxxxxxxxxxxxx # 4.12+
Signed-off-by: John Pittman <jpittman@xxxxxxxxxx>
Suggested-by: David Jeffery <djeffery@xxxxxxxxxx>
Reviewed-by: Laurence Oberman <loberman@xxxxxxxxxx>
Signed-off-by: Song Liu <songliubraving@xxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/md/raid10.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -191,7 +191,7 @@ static void * r10buf_pool_alloc(gfp_t gf
out_free_pages:
while (--j >= 0)
- resync_free_pages(&rps[j * 2]);
+ resync_free_pages(&rps[j]);
j = 0;
out_free_bio:
