On Wed, 30 Mar 2022, Greg KH wrote: > On Wed, Mar 30, 2022 at 12:01:07PM +0100, Lee Jones wrote: > > From: Xie Yongji <xieyongji@xxxxxxxxxxxxx> > > > > [ Upstream commit 57a13a5b8157d9a8606490aaa1b805bafe6c37e1 ] > > > > The block layer can't support a block size larger than > > page size yet. And a block size that's too small or > > not a power of two won't work either. If a misconfigured > > device presents an invalid block size in configuration space, > > it will result in the kernel crash something like below: > > > > [ 506.154324] BUG: kernel NULL pointer dereference, address: 0000000000000008 > > [ 506.160416] RIP: 0010:create_empty_buffers+0x24/0x100 > > [ 506.174302] Call Trace: > > [ 506.174651] create_page_buffers+0x4d/0x60 > > [ 506.175207] block_read_full_page+0x50/0x380 > > [ 506.175798] ? __mod_lruvec_page_state+0x60/0xa0 > > [ 506.176412] ? __add_to_page_cache_locked+0x1b2/0x390 > > [ 506.177085] ? blkdev_direct_IO+0x4a0/0x4a0 > > [ 506.177644] ? scan_shadow_nodes+0x30/0x30 > > [ 506.178206] ? lru_cache_add+0x42/0x60 > > [ 506.178716] do_read_cache_page+0x695/0x740 > > [ 506.179278] ? read_part_sector+0xe0/0xe0 > > [ 506.179821] read_part_sector+0x36/0xe0 > > [ 506.180337] adfspart_check_ICS+0x32/0x320 > > [ 506.180890] ? snprintf+0x45/0x70 > > [ 506.181350] ? read_part_sector+0xe0/0xe0 > > [ 506.181906] bdev_disk_changed+0x229/0x5c0 > > [ 506.182483] blkdev_get_whole+0x6d/0x90 > > [ 506.183013] blkdev_get_by_dev+0x122/0x2d0 > > [ 506.183562] device_add_disk+0x39e/0x3c0 > > [ 506.184472] virtblk_probe+0x3f8/0x79b [virtio_blk] > > [ 506.185461] virtio_dev_probe+0x15e/0x1d0 [virtio] > > > > So let's use a block layer helper to validate the block size. > > > > Signed-off-by: Xie Yongji <xieyongji@xxxxxxxxxxxxx> > > Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > > Link: https://lore.kernel.org/r/20211026144015.188-5-xieyongji@xxxxxxxxxxxxx > > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > > Signed-off-by: Lee Jones <lee.jones@xxxxxxxxxx> > > --- > > drivers/block/virtio_blk.c | 12 ++++++++++-- > > 1 file changed, 10 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c > > index 4b3645e648ee9..2af9d7c7d45cd 100644 > > --- a/drivers/block/virtio_blk.c > > +++ b/drivers/block/virtio_blk.c > > @@ -936,9 +936,17 @@ static int virtblk_probe(struct virtio_device *vdev) > > err = virtio_cread_feature(vdev, VIRTIO_BLK_F_BLK_SIZE, > > struct virtio_blk_config, blk_size, > > &blk_size); > > - if (!err) > > + if (!err) { > > + err = blk_validate_block_size(blk_size); > > + if (err) { > > + dev_err(&vdev->dev, > > + "virtio_blk: invalid block size: 0x%x\n", > > + blk_size); > > + goto out_cleanup_disk; > > + } > > + > > blk_queue_logical_block_size(q, blk_size); > > - else > > + } else > > blk_size = queue_logical_block_size(q); > > > > /* Use topology information if available */ > > You didn't build this one either :( > > {sigh} > > Care to start over? Yes, I think that's a good idea! :| </reset> -- Lee Jones [李琼斯] Principal Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog
