Patch "Netvsc: Call hv_unmap_memory() in the netvsc_device_remove()" has been added to the 5.17-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    Netvsc: Call hv_unmap_memory() in the netvsc_device_remove()

to the 5.17-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     netvsc-call-hv_unmap_memory-in-the-netvsc_device_rem.patch
and it can be found in the queue-5.17 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit e1b32870516b8ec26f75876dbde23b5bdd2c57a2
Author: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
Date:   Tue Feb 8 09:26:52 2022 -0500

    Netvsc: Call hv_unmap_memory() in the netvsc_device_remove()
    
    [ Upstream commit b539324f6fe798bdb186e4e91eafb37dd851db2a ]
    
    netvsc_device_remove() calls vunmap() inside which should not be
    called in the interrupt context. Current code calls hv_unmap_memory()
    in the free_netvsc_device() which is rcu callback and maybe called
    in the interrupt context. This will trigger BUG_ON(in_interrupt())
    in the vunmap(). Fix it via moving hv_unmap_memory() to netvsc_device_
    remove().
    
    Fixes: 846da38de0e8 ("net: netvsc: Add Isolation VM support for netvsc driver")
    Signed-off-by: Tianyu Lan <Tianyu.Lan@xxxxxxxxxxxxx>
    Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c
index afa81a9480cc..e675d1016c3c 100644
--- a/drivers/net/hyperv/netvsc.c
+++ b/drivers/net/hyperv/netvsc.c
@@ -154,19 +154,15 @@ static void free_netvsc_device(struct rcu_head *head)
 
 	kfree(nvdev->extension);
 
-	if (nvdev->recv_original_buf) {
-		hv_unmap_memory(nvdev->recv_buf);
+	if (nvdev->recv_original_buf)
 		vfree(nvdev->recv_original_buf);
-	} else {
+	else
 		vfree(nvdev->recv_buf);
-	}
 
-	if (nvdev->send_original_buf) {
-		hv_unmap_memory(nvdev->send_buf);
+	if (nvdev->send_original_buf)
 		vfree(nvdev->send_original_buf);
-	} else {
+	else
 		vfree(nvdev->send_buf);
-	}
 
 	bitmap_free(nvdev->send_section_map);
 
@@ -765,6 +761,12 @@ void netvsc_device_remove(struct hv_device *device)
 		netvsc_teardown_send_gpadl(device, net_device, ndev);
 	}
 
+	if (net_device->recv_original_buf)
+		hv_unmap_memory(net_device->recv_buf);
+
+	if (net_device->send_original_buf)
+		hv_unmap_memory(net_device->send_buf);
+
 	/* Release all resources */
 	free_netvsc_device_rcu(net_device);
 }
@@ -1821,6 +1823,12 @@ struct netvsc_device *netvsc_device_add(struct hv_device *device,
 	netif_napi_del(&net_device->chan_table[0].napi);
 
 cleanup2:
+	if (net_device->recv_original_buf)
+		hv_unmap_memory(net_device->recv_buf);
+
+	if (net_device->send_original_buf)
+		hv_unmap_memory(net_device->send_buf);
+
 	free_netvsc_device(&net_device->rcu);
 
 	return ERR_PTR(ret);