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bcache: Revert "bcache: use bvec_virt"

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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 <colyli@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org # 5.15
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211103151041.70516-1-colyli@suse.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Coly Li 2021-11-03 23:10:41 +08:00 committed by Greg Kroah-Hartman
parent d6a300977a
commit ac8ffb5d9d
1 changed files with 1 additions and 1 deletions
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2
drivers/md/bcache/btree.c
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@ -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;
}