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 @@ -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: