Commit 45422b70 authored Nov 11, 2019 by John Pittman Committed by Song Liu Nov 11, 2019

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: f0250618 ("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>

parent 228fc7d7

drivers/md/raid10.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -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:

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