From 347a529398e8e723338cca5d8a8ae2d9e7e93448 Mon Sep 17 00:00:00 2001 From: Minfei Huang Date: Tue, 9 Aug 2016 16:39:20 +0800 Subject: virtio_blk: Fix a slient kernel panic We do a lot of memory allocation in function init_vq, and don't handle the allocation failure properly. Then this function will return 0, although initialization fails due to lacking memory. At that moment, kernel will panic in guest machine, if virtio is used to drive disk. To fix this bug, we should take care of allocation failure, and return correct value to let caller know what happen. Tested-by: Chao Fan Signed-off-by: Minfei Huang Signed-off-by: Minfei Huang Reviewed-by: Cornelia Huck Reviewed-by: Stefan Hajnoczi Signed-off-by: Michael S. Tsirkin --- drivers/block/virtio_blk.c | 26 ++++++++------------------ 1 file changed, 8 insertions(+), 18 deletions(-) (limited to 'drivers/block') diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c index 1523e05..93b1aaa 100644 --- a/drivers/block/virtio_blk.c +++ b/drivers/block/virtio_blk.c @@ -391,22 +391,16 @@ static int init_vq(struct virtio_blk *vblk) num_vqs = 1; vblk->vqs = kmalloc(sizeof(*vblk->vqs) * num_vqs, GFP_KERNEL); - if (!vblk->vqs) { - err = -ENOMEM; - goto out; - } + if (!vblk->vqs) + return -ENOMEM; names = kmalloc(sizeof(*names) * num_vqs, GFP_KERNEL); - if (!names) - goto err_names; - callbacks = kmalloc(sizeof(*callbacks) * num_vqs, GFP_KERNEL); - if (!callbacks) - goto err_callbacks; - vqs = kmalloc(sizeof(*vqs) * num_vqs, GFP_KERNEL); - if (!vqs) - goto err_vqs; + if (!names || !callbacks || !vqs) { + err = -ENOMEM; + goto out; + } for (i = 0; i < num_vqs; i++) { callbacks[i] = virtblk_done; @@ -417,7 +411,7 @@ static int init_vq(struct virtio_blk *vblk) /* Discover virtqueues and write information to configuration. */ err = vdev->config->find_vqs(vdev, num_vqs, vqs, callbacks, names); if (err) - goto err_find_vqs; + goto out; for (i = 0; i < num_vqs; i++) { spin_lock_init(&vblk->vqs[i].lock); @@ -425,16 +419,12 @@ static int init_vq(struct virtio_blk *vblk) } vblk->num_vqs = num_vqs; - err_find_vqs: +out: kfree(vqs); - err_vqs: kfree(callbacks); - err_callbacks: kfree(names); - err_names: if (err) kfree(vblk->vqs); - out: return err; } -- cgit v1.1