From ac8ffb5d9dfbdb965f72732a0e214cfcdc8eb44c Mon Sep 17 00:00:00 2001 From: Coly Li Date: Wed, 3 Nov 2021 23:10:41 +0800 Subject: [PATCH] bcache: Revert "bcache: use bvec_virt" commit 2878feaed543c35f9dbbe6d8ce36fb67ac803eef upstream. This reverts commit 2fd3e5efe791946be0957c8e1eed9560b541fe46. The above commit replaces page_address(bv->bv_page) by bvec_virt(bv) to avoid directly access to bv->bv_page, but in situation bv->bv_offset is not zero and page_address(bv->bv_page) is not equal to bvec_virt(bv). In such case a memory corruption may happen because memory in next page is tainted by following line in do_btree_node_write(), memcpy(bvec_virt(bv), addr, PAGE_SIZE); This patch reverts the mentioned commit to avoid the memory corruption. Fixes: 2fd3e5efe791 ("bcache: use bvec_virt") Signed-off-by: Coly Li Cc: Christoph Hellwig Cc: stable@vger.kernel.org # 5.15 Signed-off-by: Christoph Hellwig Link: https://lore.kernel.org/r/20211103151041.70516-1-colyli@suse.de Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- drivers/md/bcache/btree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 0595559..183a58c 100644 --- a/drivers/md/bcache/btree.c +++ b/drivers/md/bcache/btree.c @@ -378,7 +378,7 @@ static void do_btree_node_write(struct btree *b) struct bvec_iter_all iter_all; bio_for_each_segment_all(bv, b->bio, iter_all) { - memcpy(bvec_virt(bv), addr, PAGE_SIZE); + memcpy(page_address(bv->bv_page), addr, PAGE_SIZE); addr += PAGE_SIZE; } -- 2.7.4