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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 v2 0/2] net: mana: Fix NULL dereferences during teardown after attach failure
Date: Fri, 22 May 2026 16:33:11 -0700	[thread overview]
Message-ID: <20260522233555.1099342-1-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 adds an early exit in mana_detach() for already-detached ports,
making it safe for non-close callers. This allows the queue reset
handler to safely retry mana_attach() without redundant teardown.

Changes in v2:
  - Patch 2: moved netif_device_present() check into mana_detach() as
    an early exit instead of using goto in the work handler 

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

 drivers/net/ethernet/microsoft/mana/mana_en.c | 76 ++++++++++++-------
 1 file changed, 47 insertions(+), 29 deletions(-)

-- 
2.43.0


             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 Dipayaan Roy [this message]
2026-05-22 23:33 ` [PATCH net v2 1/2] net: mana: Add NULL guards in teardown path to prevent panic on attach failure Dipayaan Roy
2026-05-25  8:01   ` Dipayaan Roy
2026-05-22 23:33 ` [PATCH net v2 2/2] net: mana: Skip redundant detach on already-detached port Dipayaan Roy

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