From: Haiyang Zhang <haiya...@microsoft.com>
The existing code move the VF NIC to new namespace when NETDEV_REGISTER is
received on netvsc NIC. During deletion of the namespace,
default_device_exit_batch() >> default_device_exit_net() is called. When
netvsc NIC is moved back and registered to the default namespace, it
automatically brings VF NIC back to the default namespace. This will cause
the default_device_exit_net() >> for_each_netdev_safe loop unable to detect
the list end, and hit NULL ptr:
[ 231.449420] mana 7870:00:00.0 enP30832s1: Moved VF to namespace with: eth0
[ 231.449656] BUG: kernel NULL pointer dereference, address: 0000000000000010
[ 231.450246] #PF: supervisor read access in kernel mode
[ 231.450579] #PF: error_code(0x0000) - not-present page
[ 231.450916] PGD 17b8a8067 P4D 0
[ 231.451163] Oops: Oops: 0000 [#1] SMP NOPTI
[ 231.451450] CPU: 82 UID: 0 PID: 1394 Comm: kworker/u768:1 Not tainted
6.16.0-rc4+ #3 VOLUNTARY
[ 231.452042] Hardware name: Microsoft Corporation Virtual Machine/Virtual
Machine, BIOS Hyper-V UEFI Release v4.1 11/21/2024
[ 231.452692] Workqueue: netns cleanup_net
[ 231.452947] RIP: 0010:default_device_exit_batch+0x16c/0x3f0
[ 231.453326] Code: c0 0c f5 b3 e8 d5 db fe ff 48 85 c0 74 15 48 c7 c2 f8 fd
ca b2 be 10 00 00 00 48 8d 7d c0 e8 7b 77 25 00 49 8b 86 28 01 00 00 <48> 8b 50
10 4c 8b 2a 4c 8d 62 f0 49 83 ed 10 4c 39 e0 0f 84 d6 00
[ 231.454294] RSP: 0018:ff75fc7c9bf9fd00 EFLAGS: 00010246
[ 231.454610] RAX: 0000000000000000 RBX: 0000000000000002 RCX: 61c8864680b583eb
[ 231.455094] RDX: ff1fa9f71462d800 RSI: ff75fc7c9bf9fd38 RDI: 0000000030766564
[ 231.455686] RBP: ff75fc7c9bf9fd78 R08: 0000000000000000 R09: 0000000000000000
[ 231.456126] R10: 0000000000000001 R11: 0000000000000004 R12: ff1fa9f70088e340
[ 231.456621] R13: ff1fa9f70088e340 R14: ffffffffb3f50c20 R15: ff1fa9f7103e6340
[ 231.457161] FS: 0000000000000000(0000) GS:ff1faa6783a08000(0000)
knlGS:0000000000000000
[ 231.457707] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 231.458031] CR2: 0000000000000010 CR3: 0000000179ab2006 CR4: 0000000000b73ef0
[ 231.458434] Call Trace:
[ 231.458600] <TASK>
[ 231.458777] ops_undo_list+0x100/0x220
[ 231.459015] cleanup_net+0x1b8/0x300
[ 231.459285] process_one_work+0x184/0x340
To fix it, skip the VF NIC's namespace change with netvsc when the VF
namespace is being cleaned up, because the default_device_exit_net() will
do it later.
Cc: sta...@vger.kernel.org
Fixes: 4c262801ea60 ("hv_netvsc: Fix VF namespace also in synthetic NIC
NETDEV_REGISTER event")
Signed-off-by: Haiyang Zhang <haiya...@microsoft.com>
---
drivers/net/hyperv/netvsc_drv.c | 10 +++++++++-
1 file changed, 9 insertions(+), 1 deletion(-)
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 8be9bce66a4e..8fc05a8c0018 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2788,13 +2788,21 @@ static void netvsc_event_set_vf_ns(struct net_device
*ndev)
{
struct net_device_context *ndev_ctx = netdev_priv(ndev);
struct net_device *vf_netdev;
+ struct net *vfnet;
int ret;
vf_netdev = rtnl_dereference(ndev_ctx->vf_netdev);
if (!vf_netdev)
return;
- if (!net_eq(dev_net(ndev), dev_net(vf_netdev))) {
+ vfnet = dev_net(vf_netdev);
+ /* Do not move it now if its net is being cleaned up,
+ * net_cleanup_work will move it.
+ */
+ if (llist_on_list(&vfnet->cleanup_list))
+ return;
+
+ if (!net_eq(dev_net(ndev), vfnet)) {
ret = dev_change_net_namespace(vf_netdev, dev_net(ndev),
"eth%d");
if (ret)
--
2.34.1
