From: John Pittman Date: Tue, 12 Nov 2019 00:43:20 +0000 (-0800) Subject: md/raid10: prevent access of uninitialized resync_pages offset X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=45422b704db392a6d79d07ee3e3670b11048bd53;p=linux.git md/raid10: prevent access of uninitialized resync_pages offset 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 Suggested-by: David Jeffery Reviewed-by: Laurence Oberman Signed-off-by: Song Liu --- diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 2eca0a81a8c99..ec136e44aef7f 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -191,7 +191,7 @@ static void * r10buf_pool_alloc(gfp_t gfp_flags, void *data) out_free_pages: while (--j >= 0) - resync_free_pages(&rps[j * 2]); + resync_free_pages(&rps[j]); j = 0; out_free_bio: