From 8468f45091d2866affed6f6a7aecc20779139173 Mon Sep 17 00:00:00 2001 From: Coly Li Date: Wed, 3 Nov 2021 14:49:17 +0800 Subject: bcache: fix use-after-free problem in bcache_device_free() In bcache_device_free(), pointer disk is referenced still in ida_simple_remove() after blk_cleanup_disk() gets called on this pointer. This may cause a potential panic by use-after-free on the disk pointer. This patch fixes the problem by calling blk_cleanup_disk() after ida_simple_remove(). Fixes: bc70852fd104 ("bcache: convert to blk_alloc_disk/blk_cleanup_disk") Signed-off-by: Coly Li Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Ulf Hansson Cc: stable@vger.kernel.org # v5.14+ Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20211103064917.67383-1-colyli@suse.de Signed-off-by: Jens Axboe --- drivers/md/bcache/super.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/bcache') diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c index 84a48eed8e24..a7bb3355b776 100644 --- a/drivers/md/bcache/super.c +++ b/drivers/md/bcache/super.c @@ -885,9 +885,9 @@ static void bcache_device_free(struct bcache_device *d) bcache_device_detach(d); if (disk) { - blk_cleanup_disk(disk); ida_simple_remove(&bcache_device_idx, first_minor_to_idx(disk->first_minor)); + blk_cleanup_disk(disk); } bioset_exit(&d->bio_split); -- cgit From 2878feaed543c35f9dbbe6d8ce36fb67ac803eef Mon Sep 17 00:00:00 2001 From: Coly Li Date: Wed, 3 Nov 2021 23:10:41 +0800 Subject: bcache: Revert "bcache: use bvec_virt" 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 --- drivers/md/bcache/btree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/md/bcache') diff --git a/drivers/md/bcache/btree.c b/drivers/md/bcache/btree.c index 93b67b8d31c3..88c573eeb598 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; } -- cgit