Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1947063AbbEBTen (ORCPT ); Sat, 2 May 2015 15:34:43 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:45822 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1946209AbbEBTej (ORCPT ); Sat, 2 May 2015 15:34:39 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Akinobu Mita , Sagi Grimberg , "Martin K. Petersen" , Christoph Hellwig , "James E.J. Bottomley" , Nicholas Bellinger Subject: [PATCH 3.19 109/177] target/file: Fix SG table for prot_buf initialization Date: Sat, 2 May 2015 21:02:11 +0200 Message-Id: <20150502190125.144987331@linuxfoundation.org> X-Mailer: git-send-email 2.3.7 In-Reply-To: <20150502190119.666291882@linuxfoundation.org> References: <20150502190119.666291882@linuxfoundation.org> User-Agent: quilt/0.64 MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2965 Lines: 86 3.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Akinobu Mita commit c836777830428372074d5129ac513e1472c99791 upstream. In fd_do_prot_rw(), it allocates prot_buf which is used to copy from se_cmd->t_prot_sg by sbc_dif_copy_prot(). The SG table for prot_buf is also initialized by allocating 'se_cmd->t_prot_nents' entries of scatterlist and setting the data length of each entry to PAGE_SIZE at most. However if se_cmd->t_prot_sg contains a clustered entry (i.e. sg->length > PAGE_SIZE), the SG table for prot_buf can't be initialized correctly and sbc_dif_copy_prot() can't copy to prot_buf. (This actually happened with TCM loopback fabric module) As prot_buf is allocated by kzalloc() and it's physically contiguous, we only need a single scatterlist entry. Signed-off-by: Akinobu Mita Cc: Sagi Grimberg Cc: "Martin K. Petersen" Cc: Christoph Hellwig Cc: "James E.J. Bottomley" Signed-off-by: Nicholas Bellinger Signed-off-by: Greg Kroah-Hartman --- drivers/target/target_core_file.c | 21 ++++++--------------- 1 file changed, 6 insertions(+), 15 deletions(-) --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -264,11 +264,10 @@ static int fd_do_prot_rw(struct se_cmd * struct se_device *se_dev = cmd->se_dev; struct fd_dev *dev = FD_DEV(se_dev); struct file *prot_fd = dev->fd_prot_file; - struct scatterlist *sg; loff_t pos = (cmd->t_task_lba * se_dev->prot_length); unsigned char *buf; - u32 prot_size, len, size; - int rc, ret = 1, i; + u32 prot_size; + int rc, ret = 1; prot_size = (cmd->data_length / se_dev->dev_attrib.block_size) * se_dev->prot_length; @@ -281,24 +280,16 @@ static int fd_do_prot_rw(struct se_cmd * } buf = fd_prot->prot_buf; - fd_prot->prot_sg_nents = cmd->t_prot_nents; - fd_prot->prot_sg = kzalloc(sizeof(struct scatterlist) * - fd_prot->prot_sg_nents, GFP_KERNEL); + fd_prot->prot_sg_nents = 1; + fd_prot->prot_sg = kzalloc(sizeof(struct scatterlist), + GFP_KERNEL); if (!fd_prot->prot_sg) { pr_err("Unable to allocate fd_prot->prot_sg\n"); kfree(fd_prot->prot_buf); return -ENOMEM; } sg_init_table(fd_prot->prot_sg, fd_prot->prot_sg_nents); - size = prot_size; - - for_each_sg(fd_prot->prot_sg, sg, fd_prot->prot_sg_nents, i) { - - len = min_t(u32, PAGE_SIZE, size); - sg_set_buf(sg, buf, len); - size -= len; - buf += len; - } + sg_set_buf(fd_prot->prot_sg, buf, prot_size); } if (is_write) { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/