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 2/2] net: mana: Skip redundant detach in queue reset handler if already detached
Date: Mon, 18 May 2026 12:43:51 -0700 [thread overview]
Message-ID: <20260518194654.735580-3-dipayanroy@linux.microsoft.com> (raw)
In-Reply-To: <20260518194654.735580-1-dipayanroy@linux.microsoft.com>
When mana_per_port_queue_reset_work_handler() runs, it unconditionally
calls mana_detach() which attempts to tear down queues that are already
freed, leading to NULL pointer dereferences on apc->tx_qp and
apc->rxqs.
Check netif_device_present() in the reset handler and skip
mana_detach() when the port is already in detached state. This avoids
the redundant teardown and goes directly to mana_attach() to retry
bringing the port back up.
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 | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/net/ethernet/microsoft/mana/mana_en.c b/drivers/net/ethernet/microsoft/mana/mana_en.c
index 0582803907a8..907efadf6fd6 100644
--- a/drivers/net/ethernet/microsoft/mana/mana_en.c
+++ b/drivers/net/ethernet/microsoft/mana/mana_en.c
@@ -316,12 +316,19 @@ static void mana_per_port_queue_reset_work_handler(struct work_struct *work)
goto out;
}
+ /* If already detached (indicates detach succeeded but attach failed
+ * previously). Now skip mana detach and just retry mana_attach.
+ */
+ if (!netif_device_present(ndev))
+ goto attach;
+
err = mana_detach(ndev, false);
if (err) {
netdev_err(ndev, "mana_detach failed: %d\n", err);
goto dealloc_pre_rxbufs;
}
+attach:
err = mana_attach(ndev);
if (err)
netdev_err(ndev, "mana_attach failed: %d\n", err);
--
2.43.0
next prev parent reply other threads:[~2026-05-18 19:47 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-18 19:43 [PATCH net 0/2] net: mana: Fix NULL dereferences during teardown after attach failure Dipayaan Roy
2026-05-18 19:43 ` [PATCH net 1/2] net: mana: Add NULL guards in teardown path to prevent panic on " Dipayaan Roy
2026-05-18 21:49 ` Harshitha Ramamurthy
2026-05-19 22:55 ` Jakub Kicinski
2026-05-20 18:11 ` Dipayaan Roy
2026-05-18 19:43 ` Dipayaan Roy [this message]
2026-05-19 22:55 ` [PATCH net 2/2] net: mana: Skip redundant detach in queue reset handler if already detached Jakub Kicinski
2026-05-20 18:23 ` Dipayaan Roy
2026-05-21 0:17 ` Jakub Kicinski
2026-05-22 23:16 ` Dipayaan Roy
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