From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:38996 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753467AbeBBRM0 (ORCPT ); Fri, 2 Feb 2018 12:12:26 -0500 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Guilherme G. Piccoli" , Raghava Aditya Renukunta , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 4.14 117/156] scsi: aacraid: Prevent crash in case of free interrupt during scsi EH path Date: Fri, 2 Feb 2018 17:58:18 +0100 Message-Id: <20180202140845.475716367@linuxfoundation.org> In-Reply-To: <20180202140840.242829545@linuxfoundation.org> References: <20180202140840.242829545@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: "Guilherme G. Piccoli" [ Upstream commit e4717292ddebcfe231651b5aff9fa19ca158d178 ] As part of the scsi EH path, aacraid performs a reinitialization of the adapter, which encompass freeing resources and IRQs, NULLifying lots of pointers, and then initialize it all over again. We've identified a problem during the free IRQ portion of this path if CONFIG_DEBUG_SHIRQ is enabled on kernel config file. Happens that, in case this flag was set, right after free_irq() effectively clears the interrupt, it checks if it was requested as IRQF_SHARED. In positive case, it performs another call to the IRQ handler on driver. Problem is: since aacraid currently free some resources *before* freeing the IRQ, once free_irq() path calls the handler again (due to CONFIG_DEBUG_SHIRQ), aacraid crashes due to NULL pointer dereference with the following trace: aac_src_intr_message+0xf8/0x740 [aacraid] __free_irq+0x33c/0x4a0 free_irq+0x78/0xb0 aac_free_irq+0x13c/0x150 [aacraid] aac_reset_adapter+0x2e8/0x970 [aacraid] aac_eh_reset+0x3a8/0x5d0 [aacraid] scsi_try_host_reset+0x74/0x180 scsi_eh_ready_devs+0xc70/0x1510 scsi_error_handler+0x624/0xa20 This patch prevents the crash by changing the order of the deinitialization in this path of aacraid: first we clear the IRQ, then we free other resources. No functional change intended. Signed-off-by: Guilherme G. Piccoli Reviewed-by: Raghava Aditya Renukunta Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/aacraid/commsup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/scsi/aacraid/commsup.c +++ b/drivers/scsi/aacraid/commsup.c @@ -1583,6 +1583,7 @@ static int _aac_reset_adapter(struct aac * will ensure that i/o is queisced and the card is flushed in that * case. */ + aac_free_irq(aac); aac_fib_map_free(aac); dma_free_coherent(&aac->pdev->dev, aac->comm_size, aac->comm_addr, aac->comm_phys); @@ -1590,7 +1591,6 @@ static int _aac_reset_adapter(struct aac aac->comm_phys = 0; kfree(aac->queues); aac->queues = NULL; - aac_free_irq(aac); kfree(aac->fsa_dev); aac->fsa_dev = NULL;