From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 85D438BE0 for ; Tue, 28 Mar 2023 15:01:18 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0FDAEC433D2; Tue, 28 Mar 2023 15:01:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1680015678; bh=S92CcyWhvxH5rDjNGNtndcNeQr7FnAOumVDxLSX/x6M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tU5tX8ZqI4zFhfE/6RMCD+J7/gbPUqQ6ceFATQzqZwZAWIr40y5iqajlMKMgYIWnq islbk/+W385LzdZydm1xrsRQr3lNCjAijJzJ9lbIIyxP1Ryun32A0WtqZnRT44h8Rp A4nFee8mBWaYxPZb00NXW2kCOOcW9Tw8q0cJcSLA= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jakob Koschel , Justin Tee , "Martin K. Petersen" , Sasha Levin Subject: [PATCH 6.1 135/224] scsi: lpfc: Avoid usage of list iterator variable after loop Date: Tue, 28 Mar 2023 16:42:11 +0200 Message-Id: <20230328142623.008779468@linuxfoundation.org> X-Mailer: git-send-email 2.40.0 In-Reply-To: <20230328142617.205414124@linuxfoundation.org> References: <20230328142617.205414124@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Jakob Koschel [ Upstream commit 2850b23e9f9ae3696e472d2883ea1b43aafa884e ] If the &epd_pool->list is empty when executing lpfc_get_io_buf_from_expedite_pool() the function would return an invalid pointer. Even in the case if the list is guaranteed to be populated, the iterator variable should not be used after the loop to be more robust for future changes. Linus proposed to avoid any use of the list iterator variable after the loop, in the attempt to move the list iterator variable declaration into the macro to avoid any potential misuse after the loop [1]. Link: https://lore.kernel.org/all/CAHk-=wgRr_D8CB-D9Kg-c=EHreAsk5SqXPwr9Y7k9sA6cWXJ6w@mail.gmail.com/ [1] Signed-off-by: Jakob Koschel Link: https://lore.kernel.org/r/20230301-scsi-lpfc-avoid-list-iterator-after-loop-v1-1-325578ae7561@gmail.com Reviewed-by: Justin Tee Signed-off-by: Martin K. Petersen Signed-off-by: Sasha Levin --- drivers/scsi/lpfc/lpfc_sli.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/scsi/lpfc/lpfc_sli.c b/drivers/scsi/lpfc/lpfc_sli.c index 43e06bb917e77..b44bb3ae22ad9 100644 --- a/drivers/scsi/lpfc/lpfc_sli.c +++ b/drivers/scsi/lpfc/lpfc_sli.c @@ -21886,20 +21886,20 @@ lpfc_get_io_buf_from_private_pool(struct lpfc_hba *phba, static struct lpfc_io_buf * lpfc_get_io_buf_from_expedite_pool(struct lpfc_hba *phba) { - struct lpfc_io_buf *lpfc_ncmd; + struct lpfc_io_buf *lpfc_ncmd = NULL, *iter; struct lpfc_io_buf *lpfc_ncmd_next; unsigned long iflag; struct lpfc_epd_pool *epd_pool; epd_pool = &phba->epd_pool; - lpfc_ncmd = NULL; spin_lock_irqsave(&epd_pool->lock, iflag); if (epd_pool->count > 0) { - list_for_each_entry_safe(lpfc_ncmd, lpfc_ncmd_next, + list_for_each_entry_safe(iter, lpfc_ncmd_next, &epd_pool->list, list) { - list_del(&lpfc_ncmd->list); + list_del(&iter->list); epd_pool->count--; + lpfc_ncmd = iter; break; } } -- 2.39.2