lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Date: Tue, 1 Sep 2020 17:09:03 +0200 From: Greg Kroah-Hartman <gregkh@...uxfoundation.org> To: linux-kernel@...r.kernel.org Cc: Greg Kroah-Hartman <gregkh@...uxfoundation.org>, stable@...r.kernel.org, Ming Lei <ming.lei@...hat.com>, Christoph Hellwig <hch@....de>, Changpeng Liu <changpeng.liu@...el.com>, Daniel Verkamp <dverkamp@...omium.org>, "Michael S. Tsirkin" <mst@...hat.com>, Stefan Hajnoczi <stefanha@...hat.com>, Stefano Garzarella <sgarzare@...hat.com>, Jens Axboe <axboe@...nel.dk>, Sasha Levin <sashal@...nel.org> Subject: [PATCH 5.8 087/255] block: virtio_blk: fix handling single range discard request From: Ming Lei <ming.lei@...hat.com> [ Upstream commit af822aa68fbdf0a480a17462ed70232998127453 ] 1f23816b8eb8 ("virtio_blk: add discard and write zeroes support") starts to support multi-range discard for virtio-blk. However, the virtio-blk disk may report max discard segment as 1, at least that is exactly what qemu is doing. So far, block layer switches to normal request merge if max discard segment limit is 1, and multiple bios can be merged to single segment. This way may cause memory corruption in virtblk_setup_discard_write_zeroes(). Fix the issue by handling single max discard segment in straightforward way. Fixes: 1f23816b8eb8 ("virtio_blk: add discard and write zeroes support") Signed-off-by: Ming Lei <ming.lei@...hat.com> Reviewed-by: Christoph Hellwig <hch@....de> Cc: Changpeng Liu <changpeng.liu@...el.com> Cc: Daniel Verkamp <dverkamp@...omium.org> Cc: Michael S. Tsirkin <mst@...hat.com> Cc: Stefan Hajnoczi <stefanha@...hat.com> Cc: Stefano Garzarella <sgarzare@...hat.com> Signed-off-by: Jens Axboe <axboe@...nel.dk> Signed-off-by: Sasha Levin <sashal@...nel.org> --- drivers/block/virtio_blk.c | 31 +++++++++++++++++++++++-------- 1 file changed, 23 insertions(+), 8 deletions(-) diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 980df853ee497..99991b6a6f0ed 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -126,16 +126,31 @@ static int virtblk_setup_discard_write_zeroes(struct request *req, bool unmap) if (!range) return -ENOMEM; - __rq_for_each_bio(bio, req) { - u64 sector = bio->bi_iter.bi_sector; - u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; - - range[n].flags = cpu_to_le32(flags); - range[n].num_sectors = cpu_to_le32(num_sectors); - range[n].sector = cpu_to_le64(sector); - n++; + /* + * Single max discard segment means multi-range discard isn't + * supported, and block layer only runs contiguity merge like + * normal RW request. So we can't reply on bio for retrieving + * each range info. + */ + if (queue_max_discard_segments(req->q) == 1) { + range[0].flags = cpu_to_le32(flags); + range[0].num_sectors = cpu_to_le32(blk_rq_sectors(req)); + range[0].sector = cpu_to_le64(blk_rq_pos(req)); + n = 1; + } else { + __rq_for_each_bio(bio, req) { + u64 sector = bio->bi_iter.bi_sector; + u32 num_sectors = bio->bi_iter.bi_size >> SECTOR_SHIFT; + + range[n].flags = cpu_to_le32(flags); + range[n].num_sectors = cpu_to_le32(num_sectors); + range[n].sector = cpu_to_le64(sector); + n++; + } } + WARN_ON_ONCE(n != segments); + req->special_vec.bv_page = virt_to_page(range); req->special_vec.bv_offset = offset_in_page(range); req->special_vec.bv_len = sizeof(*range) * segments; -- 2.25.1
Powered by blists - more mailing lists