| From 45422b704db392a6d79d07ee3e3670b11048bd53 Mon Sep 17 00:00:00 2001 |
| From: John Pittman <jpittman@redhat.com> |
| Date: Mon, 11 Nov 2019 16:43:20 -0800 |
| Subject: md/raid10: prevent access of uninitialized resync_pages offset |
| |
| From: John Pittman <jpittman@redhat.com> |
| |
| 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@vger.kernel.org # 4.12+ |
| Signed-off-by: John Pittman <jpittman@redhat.com> |
| Suggested-by: David Jeffery <djeffery@redhat.com> |
| Reviewed-by: Laurence Oberman <loberman@redhat.com> |
| Signed-off-by: Song Liu <songliubraving@fb.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/md/raid10.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| --- a/drivers/md/raid10.c |
| +++ b/drivers/md/raid10.c |
| @@ -226,7 +226,7 @@ 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: |
