From: Gautam Dawar <gdawar.xilinx@gmail.com>
To: mst@redhat.com
Cc: martinh@xilinx.com, hanand@xilinx.com, gdawar@xilinx.com,
Gautam Dawar <gdawar.xilinx@gmail.com>,
Jason Wang <jasowang@redhat.com>,
Zhu Lingshan <lingshan.zhu@intel.com>,
kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] vhost_vdpa: fix the missing irq_bypass_unregister_producer() invocation
Date: Wed, 24 Feb 2021 17:18:45 +0530 [thread overview]
Message-ID: <20210224114845.104173-1-gdawar.xilinx@gmail.com> (raw)
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: 2cf1ba9a4d15c ("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>
---
drivers/vhost/vdpa.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 62a9bb0efc55..e00573b87aba 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -844,14 +844,10 @@ 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)
--
2.30.1
WARNING: multiple messages have this Message-ID (diff)
From: Gautam Dawar <gdawar.xilinx@gmail.com>
To: mst@redhat.com
Cc: kvm@vger.kernel.org, netdev@vger.kernel.org,
Gautam Dawar <gdawar.xilinx@gmail.com>,
linux-kernel@vger.kernel.org, gdawar@xilinx.com,
virtualization@lists.linux-foundation.org, martinh@xilinx.com,
hanand@xilinx.com, Zhu Lingshan <lingshan.zhu@intel.com>
Subject: [PATCH] vhost_vdpa: fix the missing irq_bypass_unregister_producer() invocation
Date: Wed, 24 Feb 2021 17:18:45 +0530 [thread overview]
Message-ID: <20210224114845.104173-1-gdawar.xilinx@gmail.com> (raw)
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: 2cf1ba9a4d15c ("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>
---
drivers/vhost/vdpa.c | 8 ++------
1 file changed, 2 insertions(+), 6 deletions(-)
diff --git a/drivers/vhost/vdpa.c b/drivers/vhost/vdpa.c
index 62a9bb0efc55..e00573b87aba 100644
--- a/drivers/vhost/vdpa.c
+++ b/drivers/vhost/vdpa.c
@@ -844,14 +844,10 @@ 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)
--
2.30.1
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next reply other threads:[~2021-02-24 11:50 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-24 11:48 Gautam Dawar [this message]
2021-02-24 11:48 ` [PATCH] vhost_vdpa: fix the missing irq_bypass_unregister_producer() invocation Gautam Dawar
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