From: Dipayaan Roy <dipayanroy@linux.microsoft.com>
To: kys@microsoft.com, haiyangz@microsoft.com, wei.liu@kernel.org,
decui@microsoft.com, andrew+netdev@lunn.ch, davem@davemloft.net,
edumazet@google.com, kuba@kernel.org, pabeni@redhat.com,
leon@kernel.org, longli@microsoft.com, kotaranov@microsoft.com,
horms@kernel.org, shradhagupta@linux.microsoft.com,
ssengar@linux.microsoft.com, ernis@linux.microsoft.com,
shirazsaleem@microsoft.com, linux-hyperv@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
linux-rdma@vger.kernel.org, stephen@networkplumber.org,
jacob.e.keller@intel.com, dipayanroy@microsoft.com,
leitao@debian.org, kees@kernel.org, john.fastabend@gmail.com,
hawk@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net,
ast@kernel.org, sdf@fomichev.me, yury.norov@gmail.com
Subject: [PATCH net v2 2/2] net: mana: Skip redundant detach on already-detached port
Date: Fri, 22 May 2026 16:33:13 -0700 [thread overview]
Message-ID: <20260522233555.1099342-3-dipayanroy@linux.microsoft.com> (raw)
In-Reply-To: <20260522233555.1099342-1-dipayanroy@linux.microsoft.com>
When mana_per_port_queue_reset_work_handler() runs after a previous
detach succeeded but attach failed, the port is left in a detached
state with apc->tx_qp and apc->rxqs already freed. Calling
mana_detach() again unconditionally leads to NULL pointer dereferences
during queue teardown.
Add an early exit in mana_detach() when the port is already in
detached state (!netif_device_present) for non-close callers, making
it safe to call idempotently. This allows the queue reset handler and
other recovery paths to simply retry mana_attach() without redundant
teardown.
Fixes: 3b194343c250 ("net: mana: Implement ndo_tx_timeout and serialize queue resets per port.")
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: Dipayaan Roy <dipayanroy@linux.microsoft.com>
---
drivers/net/ethernet/microsoft/mana/mana_en.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 0582803907a8..1e1ad2795c3c 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -3350,6 +3350,12 @@ int mana_detach(struct net_device *ndev, bool from_close)
ASSERT_RTNL();
+ /* If already detached (indicates detach succeeded but attach failed
+ * previously). Now skip mana detach and just retry mana_attach.
+ */
+ if (!from_close && !netif_device_present(ndev))
+ return 0;
+
apc->port_st_save = apc->port_is_up;
apc->port_is_up = false;
--
2.43.0
prev parent reply other threads:[~2026-05-22 23:36 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-22 23:33 [PATCH net v2 0/2] net: mana: Fix NULL dereferences during teardown after attach failure Dipayaan Roy
2026-05-22 23:33 ` [PATCH net v2 1/2] net: mana: Add NULL guards in teardown path to prevent panic on " Dipayaan Roy
2026-05-22 23:33 ` Dipayaan Roy [this message]
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