From 2269848386c4b8395bc67eaaf7d08011da7c07ef Mon Sep 17 00:00:00 2001 From: Varun Prakash Date: Wed, 11 Oct 2017 19:33:21 +0530 Subject: [PATCH] scsi: libcxgbi: simplify task->hdr allocation for mgmt cmds In case of mgmt cmds, task->hdr is dereferenced after transmitting the pdu in iscsi_tcp_task_xmit(). To handle this case current code increments the Tx skb reference count and frees the skb in cxgbi_cleanup_task(). In some error cases this results in skb leak. To fix this in case of mgmt cmds, allocate a separate buffer for iSCSI hdr and free this buffer in cxgbi_cleanup_task(). Signed-off-by: Varun Prakash Signed-off-by: Martin K. Petersen --- drivers/scsi/cxgbi/libcxgbi.c | 43 +++++++++++++++++++++++------------ drivers/scsi/cxgbi/libcxgbi.h | 1 - 2 files changed, 28 insertions(+), 16 deletions(-) diff --git a/drivers/scsi/cxgbi/libcxgbi.c b/drivers/scsi/cxgbi/libcxgbi.c index f39d4d107114..858e32e8ad2d 100644 --- a/drivers/scsi/cxgbi/libcxgbi.c +++ b/drivers/scsi/cxgbi/libcxgbi.c @@ -1887,16 +1887,13 @@ int cxgbi_conn_alloc_pdu(struct iscsi_task *task, u8 opcode) struct iscsi_tcp_task *tcp_task = task->dd_data; struct cxgbi_task_data *tdata = iscsi_task_cxgbi_data(task); struct scsi_cmnd *sc = task->sc; + struct cxgbi_sock *csk = cconn->cep->csk; + struct net_device *ndev = cdev->ports[csk->port_id]; int headroom = SKB_TX_ISCSI_PDU_HEADER_MAX; tcp_task->dd_data = tdata; task->hdr = NULL; - if (tdata->skb) { - kfree_skb(tdata->skb); - tdata->skb = NULL; - } - if (SKB_MAX_HEAD(cdev->skb_tx_rsvd) > (512 * MAX_SKB_FRAGS) && (opcode == ISCSI_OP_SCSI_DATA_OUT || (opcode == ISCSI_OP_SCSI_CMD && @@ -1908,15 +1905,23 @@ int cxgbi_conn_alloc_pdu(struct iscsi_task *task, u8 opcode) tdata->skb = alloc_skb(cdev->skb_tx_rsvd + headroom, GFP_ATOMIC); if (!tdata->skb) { - struct cxgbi_sock *csk = cconn->cep->csk; - struct net_device *ndev = cdev->ports[csk->port_id]; ndev->stats.tx_dropped++; return -ENOMEM; } - skb_get(tdata->skb); skb_reserve(tdata->skb, cdev->skb_tx_rsvd); - task->hdr = (struct iscsi_hdr *)tdata->skb->data; + + if (task->sc) { + task->hdr = (struct iscsi_hdr *)tdata->skb->data; + } else { + task->hdr = kzalloc(SKB_TX_ISCSI_PDU_HEADER_MAX, GFP_KERNEL); + if (!task->hdr) { + __kfree_skb(tdata->skb); + tdata->skb = NULL; + ndev->stats.tx_dropped++; + return -ENOMEM; + } + } task->hdr_max = SKB_TX_ISCSI_PDU_HEADER_MAX; /* BHS + AHS */ /* data_out uses scsi_cmd's itt */ @@ -2060,9 +2065,9 @@ int cxgbi_conn_xmit_pdu(struct iscsi_task *task) unsigned int datalen; int err; - if (!skb || cxgbi_skcb_test_flag(skb, SKCBF_TX_DONE)) { + if (!skb) { log_debug(1 << CXGBI_DBG_ISCSI | 1 << CXGBI_DBG_PDU_TX, - "task 0x%p, skb 0x%p\n", task, skb); + "task 0x%p\n", task); return 0; } @@ -2074,6 +2079,7 @@ int cxgbi_conn_xmit_pdu(struct iscsi_task *task) return -EPIPE; } + tdata->skb = NULL; datalen = skb->data_len; /* write ppod first if using ofldq to write ppod */ @@ -2087,6 +2093,9 @@ int cxgbi_conn_xmit_pdu(struct iscsi_task *task) /* continue. Let fl get the data */ } + if (!task->sc) + memcpy(skb->data, task->hdr, SKB_TX_ISCSI_PDU_HEADER_MAX); + err = cxgbi_sock_send_pdus(cconn->cep->csk, skb); if (err > 0) { int pdulen = err; @@ -2102,7 +2111,6 @@ int cxgbi_conn_xmit_pdu(struct iscsi_task *task) pdulen += ISCSI_DIGEST_SIZE; task->conn->txdata_octets += pdulen; - cxgbi_skcb_set_flag(skb, SKCBF_TX_DONE); return 0; } @@ -2111,6 +2119,7 @@ int cxgbi_conn_xmit_pdu(struct iscsi_task *task) "task 0x%p, skb 0x%p, len %u/%u, %d EAGAIN.\n", task, skb, skb->len, skb->data_len, err); /* reset skb to send when we are called again */ + tdata->skb = skb; return err; } @@ -2118,8 +2127,7 @@ int cxgbi_conn_xmit_pdu(struct iscsi_task *task) "itt 0x%x, skb 0x%p, len %u/%u, xmit err %d.\n", task->itt, skb, skb->len, skb->data_len, err); - __kfree_skb(tdata->skb); - tdata->skb = NULL; + __kfree_skb(skb); iscsi_conn_printk(KERN_ERR, task->conn, "xmit err %d.\n", err); iscsi_conn_failure(task->conn, ISCSI_ERR_XMIT_FAILED); @@ -2144,9 +2152,14 @@ void cxgbi_cleanup_task(struct iscsi_task *task) task, tdata->skb, task->hdr_itt); tcp_task->dd_data = NULL; + + if (!task->sc) + kfree(task->hdr); + task->hdr = NULL; + /* never reached the xmit task callout */ if (tdata->skb) { - kfree_skb(tdata->skb); + __kfree_skb(tdata->skb); tdata->skb = NULL; } diff --git a/drivers/scsi/cxgbi/libcxgbi.h b/drivers/scsi/cxgbi/libcxgbi.h index 31a5816c2e8d..dcb190e75343 100644 --- a/drivers/scsi/cxgbi/libcxgbi.h +++ b/drivers/scsi/cxgbi/libcxgbi.h @@ -205,7 +205,6 @@ enum cxgbi_skcb_flags { SKCBF_TX_NEED_HDR, /* packet needs a header */ SKCBF_TX_MEM_WRITE, /* memory write */ SKCBF_TX_FLAG_COMPL, /* wr completion flag */ - SKCBF_TX_DONE, /* skb tx done */ SKCBF_RX_COALESCED, /* received whole pdu */ SKCBF_RX_HDR, /* received pdu header */ SKCBF_RX_DATA, /* received pdu payload */ -- 2.30.2