[PATCH net v2] net/mana: Fix auxiliary device double-delete race

Konstantin Taranov
2026-03-17T14:39:43Z

From: Shiraz Saleem <shirazsaleem@microsoft.com>

Make remove_adev() safe to call concurrently from the service reset
and PCI eject paths by using xchg() to atomically claim the adev
pointer. This prevents double auxiliary_device_delete/uninit when
hv_eject_device_work races with the service reset workqueue.

Fixes: 505cc26bcae0 ("net: mana: Add support for auxiliary device servicing events")
Signed-off-by: Shiraz Saleem <shirazsaleem@microsoft.com>
Signed-off-by: Konstantin Taranov <kotaranov@microsoft.com>
Reviewed-by: Long Li <longli@microsoft.com>
---
v2: rebased on the latest net
drivers/net/ethernet/microsoft/mana/mana_en.c | 18 ++++++++++--------
1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 9017e806e..9ae5f01d8 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -3410,14 +3410,18 @@ static void adev_release(struct device *dev)

static void remove_adev(struct gdma_dev *gd)
{
- struct auxiliary_device *adev = gd->adev;
- int id = adev->id;
+ struct auxiliary_device *adev = xchg(&gd->adev, NULL);
+ int id;
+
+ if (!adev)
+ return;
+
+ id = adev->id;

auxiliary_device_delete(adev);
auxiliary_device_uninit(adev);

mana_adev_idx_free(id);
- gd->adev = NULL;
}

static int add_adev(struct gdma_dev *gd, const char *name)
@@ -3481,7 +3485,7 @@ static void mana_rdma_service_handle(struct work_struct *work)

switch (serv_work->event) {
case GDMA_SERVICE_TYPE_RDMA_SUSPEND:
- if (!gd->adev || gd->is_suspended)
+ if (gd->is_suspended)
break;

remove_adev(gd);
@@ -3684,8 +3688,7 @@ void mana_remove(struct gdma_dev *gd, bool suspending)
cancel_delayed_work_sync(&ac->gf_stats_work);

/* adev currently doesn't support suspending, always remove it */
- if (gd->adev)
- remove_adev(gd);
+ remove_adev(gd);

for (i = 0; i < ac->num_ports; i++) {
ndev = ac->ports[i];
@@ -3774,8 +3777,7 @@ void mana_rdma_remove(struct gdma_dev *gd)
if (gc->service_wq)
flush_workqueue(gc->service_wq);

- if (gd->adev)
- remove_adev(gd);
+ remove_adev(gd);

mana_gd_deregister_device(gd);
}
--
2.43.0