net: mana: Guard mana_remove against double invocation

If PM resume fails (e.g., mana_attach() returns an error), mana_probe()
calls mana_remove(), which tears down the device and sets
gd->gdma_context = NULL and gd->driver_data = NULL.

However, a failed resume callback does not automatically unbind the
driver. When the device is eventually unbound, mana_remove() is invoked
a second time. Without a NULL check, it dereferences gc->dev with
gc == NULL, causing a kernel panic.

Add an early return if gdma_context or driver_data is NULL so the second
invocation is harmless. Move the dev = gc->dev assignment after the
guard so it cannot dereference NULL.

Fixes: 635096a86edb ("net: mana: Support hibernation and kexec")
Signed-off-by: Erni Sri Satya Vennela <ernis@linux.microsoft.com>
Link: https://patch.msgid.link/20260420124741.1056179-4-ernis@linux.microsoft.com
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 468ed60a8a00b927ac331b5f39361fea9cdf1457..ce1b7ec46a27cda9270066d5b456390996d4e557 100644 (file)
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -3731,11 +3731,16 @@ void mana_remove(struct gdma_dev *gd, bool suspending)
        struct gdma_context *gc = gd->gdma_context;
        struct mana_context *ac = gd->driver_data;
        struct mana_port_context *apc;
-       struct device *dev = gc->dev;
+       struct device *dev;
        struct net_device *ndev;
        int err;
        int i;
 
+       if (!gc || !ac)
+               return;
+
+       dev = gc->dev;
+
        disable_work_sync(&ac->link_change_work);
        cancel_delayed_work_sync(&ac->gf_stats_work);