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vhost_vdpa: fix the missing irq_bypass_unregister_producer() invocation

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commit 4c050286bb upstream.

When qemu with vhost-vdpa netdevice is run for the first time,
it works well. But after the VM is powered off, the next qemu run
causes kernel panic due to a NULL pointer dereference in
irq_bypass_register_producer().

When the VM is powered off, vhost_vdpa_clean_irq() misses on calling
irq_bypass_unregister_producer() for irq 0 because of the existing check.

This leaves stale producer nodes, which are reset in
vhost_vring_call_reset() when vhost_dev_init() is invoked during the
second qemu run.

As the node member of struct irq_bypass_producer is also initialized
to zero, traversal on the producers list causes crash due to NULL
pointer dereference.

Fixes: 2cf1ba9a4d ("vhost_vdpa: implement IRQ offloading in vhost_vdpa")
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=211711
Signed-off-by: Gautam Dawar <gdawar.xilinx@gmail.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20210224114845.104173-1-gdawar.xilinx@gmail.com
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Gautam Dawar 2021-02-24 17:18:45 +05:30 committed by Greg Kroah-Hartman
parent 3e5a1bb6ea
commit 2ea2d3a798
1 changed files with 2 additions and 6 deletions
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8
drivers/vhost/vdpa.c
View File

@ -910,14 +910,10 @@ static int vhost_vdpa_open(struct inode *inode, struct file *filep)
static void vhost_vdpa_clean_irq(struct vhost_vdpa *v)
{
struct vhost_virtqueue *vq;
int i;
for (i = 0; i < v->nvqs; i++) {
vq = &v->vqs[i];
if (vq->call_ctx.producer.irq)
irq_bypass_unregister_producer(&vq->call_ctx.producer);
}
for (i = 0; i < v->nvqs; i++)
vhost_vdpa_unsetup_vq_irq(v, i);
}
static int vhost_vdpa_release(struct inode *inode, struct file *filep)