From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jia-Ju Bai Subject: [PATCH] scsi: lpfc: Fix a possible sleep-in-atomic-context bug in lpfc_mbuf_alloc() Date: Sat, 15 Sep 2018 11:42:00 +0800 Message-ID: <20180915034200.6706-1-baijiaju1990@gmail.com> Return-path: Sender: linux-kernel-owner@vger.kernel.org To: james.smart@broadcom.com, dick.kennedy@broadcom.com, jejb@linux.vnet.ibm.com, martin.petersen@oracle.com Cc: linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org, Jia-Ju Bai List-Id: linux-scsi@vger.kernel.org The driver may sleep with holding a spinlock. The function call path (from bottom to top) in Linux-4.17 is: [FUNC] dma_pool_alloc(GFP_KERNEL) drivers/scsi/lpfc/lpfc_mem.c, 400: dma_pool_alloc in lpfc_mbuf_alloc drivers/scsi/lpfc/lpfc_els.c, 228: lpfc_mbuf_alloc in lpfc_prep_els_iocb drivers/scsi/lpfc/lpfc_els.c, 2010: lpfc_prep_els_iocb in lpfc_issue_els_plogi drivers/scsi/lpfc/lpfc_els.c, 4914: lpfc_issue_els_plogi in lpfc_els_disc_plogi drivers/scsi/lpfc/lpfc_els.c, 1486: lpfc_els_disc_plogi in lpfc_more_plogi drivers/scsi/lpfc/lpfc_els.c, 3123: lpfc_more_plogi in lpfc_cancel_retry_delay_tmo drivers/scsi/lpfc/lpfc_nportdisc.c, 279: lpfc_cancel_retry_delay_tmo in lpfc_els_abort drivers/scsi/lpfc/lpfc_nportdisc.c, 236: spin_lock_irq in lpfc_els_abort To fix this bug, GFP_KERNEL is replaced with GFP_ATOMIC. This bug is found by my static analysis tool DSAC. Signed-off-by: Jia-Ju Bai --- drivers/scsi/lpfc/lpfc_mem.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/scsi/lpfc/lpfc_mem.c b/drivers/scsi/lpfc/lpfc_mem.c index 9c22a2c93462..7eae5508bfa3 100644 --- a/drivers/scsi/lpfc/lpfc_mem.c +++ b/drivers/scsi/lpfc/lpfc_mem.c @@ -398,7 +398,7 @@ lpfc_mbuf_alloc(struct lpfc_hba *phba, int mem_flags, dma_addr_t *handle) unsigned long iflags; void *ret; - ret = dma_pool_alloc(phba->lpfc_mbuf_pool, GFP_KERNEL, handle); + ret = dma_pool_alloc(phba->lpfc_mbuf_pool, GFP_ATOMIC, handle); spin_lock_irqsave(&phba->hbalock, iflags); if (!ret && (mem_flags & MEM_PRI) && pool->current_count) { -- 2.17.0