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virtio_blk: Fix a slient kernel panic

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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 <fanc.fnst@cn.fujitsu.com>
Signed-off-by: Minfei Huang <mnghuan@gmail.com>
Signed-off-by: Minfei Huang <minfei.hmf@alibaba-inc.com>
Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
This commit is contained in:
Minfei Huang 2016-08-09 16:39:20 +08:00 committed by Michael S. Tsirkin
parent 28ad55578b
commit 347a529398
1 changed files with 9 additions and 19 deletions
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28
drivers/block/virtio_blk.c
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@ -391,23 +391,17 @@ static int init_vq(struct virtio_blk *vblk)
num_vqs = 1;
vblk->vqs = kmalloc(sizeof(*vblk->vqs) * num_vqs, GFP_KERNEL);
if (!vblk->vqs) {
if (!vblk->vqs)
return -ENOMEM;
names = kmalloc(sizeof(*names) * num_vqs, GFP_KERNEL);
callbacks = kmalloc(sizeof(*callbacks) * num_vqs, GFP_KERNEL);
vqs = kmalloc(sizeof(*vqs) * num_vqs, GFP_KERNEL);
if (!names || !callbacks || !vqs) {
err = -ENOMEM;
goto out;
}
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;
for (i = 0; i < num_vqs; i++) {
callbacks[i] = virtblk_done;
snprintf(vblk->vqs[i].name, VQ_NAME_LEN, "req.%d", i);
@ -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;
}