Return-path: Received: from mail-pf0-f178.google.com ([209.85.192.178]:34389 "EHLO mail-pf0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1164693AbdEYALi (ORCPT ); Wed, 24 May 2017 20:11:38 -0400 Received: by mail-pf0-f178.google.com with SMTP id 9so150117018pfj.1 for ; Wed, 24 May 2017 17:11:38 -0700 (PDT) From: Brian Norris To: Ganapathi Bhat , Nishant Sarmukadam Cc: , Dmitry Torokhov , Amitkumar Karwar , Kalle Valo , linux-wireless@vger.kernel.org, Brian Norris Subject: [PATCH 04/14] mwifiex: pcie: don't allow cmd buffer reuse after reset Date: Wed, 24 May 2017 17:11:09 -0700 Message-Id: <20170525001119.64791-4-briannorris@chromium.org> (sfid-20170525_021431_582981_A68F7E72) In-Reply-To: <20170525001119.64791-1-briannorris@chromium.org> References: <20170525001119.64791-1-briannorris@chromium.org> Sender: linux-wireless-owner@vger.kernel.org List-ID: In rogue cases (due to other bugs) it's possible we try to process an old command response *after* resetting the device. This could trigger a double-free (or the SKB can get reallocated elsewhere...causing other memory corruptions) in mwifiex_pcie_process_cmd_complete(). For safety (and symmetry) let's always NULL out the command buffer as we free it up. We're already doing this for the command response buffer. Signed-off-by: Brian Norris --- drivers/net/wireless/marvell/mwifiex/pcie.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/marvell/mwifiex/pcie.c b/drivers/net/wireless/marvell/mwifiex/pcie.c index ea75315bf19d..3d5c29d79609 100644 --- a/drivers/net/wireless/marvell/mwifiex/pcie.c +++ b/drivers/net/wireless/marvell/mwifiex/pcie.c @@ -1060,12 +1060,14 @@ static int mwifiex_pcie_delete_cmdrsp_buf(struct mwifiex_adapter *adapter) mwifiex_unmap_pci_memory(adapter, card->cmdrsp_buf, PCI_DMA_FROMDEVICE); dev_kfree_skb_any(card->cmdrsp_buf); + card->cmdrsp_buf = NULL; } if (card && card->cmd_buf) { mwifiex_unmap_pci_memory(adapter, card->cmd_buf, PCI_DMA_TODEVICE); dev_kfree_skb_any(card->cmd_buf); + card->cmd_buf = NULL; } return 0; } @@ -2946,7 +2948,6 @@ static void mwifiex_pcie_free_buffers(struct mwifiex_adapter *adapter) mwifiex_pcie_delete_evtbd_ring(adapter); mwifiex_pcie_delete_rxbd_ring(adapter); mwifiex_pcie_delete_txbd_ring(adapter); - card->cmdrsp_buf = NULL; } /* -- 2.13.0.219.gdb65acc882-goog