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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 0/2] net: mana: Fix NULL dereferences during teardown after attach failure.
Date: Mon, 18 May 2026 12:43:49 -0700	[thread overview]
Message-ID: <20260518194654.735580-1-dipayanroy@linux.microsoft.com> (raw)

When mana_attach() fails (e.g. during queue allocation), the error
cleanup frees apc->tx_qp and apc->rxqs and sets them to NULL. Multiple
subsequent teardown paths can then dereference these NULL pointers,
causing kernel panics.

Patch 1 adds NULL guards in the low-level teardown functions
(mana_fence_rqs, mana_destroy_vport, mana_dealloc_queues) so they are
safe to call regardless of queue initialization state. This covers all
callers: mana_remove(), mana_change_mtu() recovery, and internal error
paths in mana_alloc_queues().

Patch 2 addresses the queue reset work handler specifically, where an
unconditional mana_detach() on an already-detached port caused
redundant teardown. It checks netif_device_present() to skip the detach
and directly retry mana_attach().

Dipayaan Roy (2):
  net: mana: Add NULL guards in teardown path to prevent panic on attach
    failure
  net: mana: Skip redundant detach in queue reset handler if already
    detached

 drivers/net/ethernet/microsoft/mana/mana_en.c | 77 ++++++++++++-------
 1 file changed, 48 insertions(+), 29 deletions(-)

-- 
2.43.0


             reply	other threads:[~2026-05-18 19:47 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-18 19:43 Dipayaan Roy [this message]
2026-05-18 19:43 ` [PATCH net 1/2] net: mana: Add NULL guards in teardown path to prevent panic on attach failure Dipayaan Roy
2026-05-18 21:49   ` Harshitha Ramamurthy
2026-05-18 19:43 ` [PATCH net 2/2] net: mana: Skip redundant detach in queue reset handler if already detached Dipayaan Roy

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