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: 4+ 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
2026-05-25 8:01 ` Dipayaan Roy
2026-05-22 23:33 ` Dipayaan Roy [this message]
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