iwlwifi: replace sprintf with scnprintf for debugfs output

The buffersize allocated is not accurate.
Writing to these buffers with scnprintf is safer.

Signed-off-by: Abhijeet Kolekar <abhijeet.kolekar@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 43 insertions, 28 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-debugfs.c b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
index 23632e54aab2..cbea477eb078 100644
--- a/drivers/net/wireless/iwlwifi/iwl-debugfs.c
+++ b/drivers/net/wireless/iwlwifi/iwl-debugfs.c
@@ -102,10 +102,14 @@ static ssize_t iwl_dbgfs_tx_statistics_read(struct file *file,
         struct iwl_priv *priv = (struct iwl_priv *)file->private_data;
         char buf[256];
         int pos = 0;
+        const size_t bufsz = sizeof(buf);
 
-        pos += sprintf(buf+pos, "mgmt: %u\n", priv->tx_stats[0].cnt);
-        pos += sprintf(buf+pos, "ctrl: %u\n", priv->tx_stats[1].cnt);
-        pos += sprintf(buf+pos, "data: %u\n", priv->tx_stats[2].cnt);
+        pos += scnprintf(buf + pos, bufsz - pos, "mgmt: %u\n",
+                                                priv->tx_stats[0].cnt);
+        pos += scnprintf(buf + pos, bufsz - pos, "ctrl: %u\n",
+                                                priv->tx_stats[1].cnt);
+        pos += scnprintf(buf + pos, bufsz - pos, "data: %u\n",
+                                                priv->tx_stats[2].cnt);
 
         return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
 }
@@ -117,10 +121,14 @@ static ssize_t iwl_dbgfs_rx_statistics_read(struct file *file,
         struct iwl_priv *priv = (struct iwl_priv *)file->private_data;
         char buf[256];
         int pos = 0;
+        const size_t bufsz = sizeof(buf);
 
-        pos += sprintf(buf+pos, "mgmt: %u\n", priv->rx_stats[0].cnt);
-        pos += sprintf(buf+pos, "ctrl: %u\n", priv->rx_stats[1].cnt);
-        pos += sprintf(buf+pos, "data: %u\n", priv->rx_stats[2].cnt);
+        pos += scnprintf(buf + pos, bufsz - pos, "mgmt: %u\n",
+                                                priv->rx_stats[0].cnt);
+        pos += scnprintf(buf + pos, bufsz - pos, "ctrl: %u\n",
+                                                priv->rx_stats[1].cnt);
+        pos += scnprintf(buf + pos, bufsz - pos, "data: %u\n",
+                                                priv->rx_stats[2].cnt);
 
         return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
 }
@@ -138,6 +146,7 @@ static ssize_t iwl_dbgfs_sram_read(struct file *file,
         int i;
         int pos = 0;
         struct iwl_priv *priv = (struct iwl_priv *)file->private_data;
+        const size_t bufsz = sizeof(buf);
 
         printk(KERN_DEBUG "offset is: 0x%x\tlen is: 0x%x\n",
         priv->dbgfs->sram_offset, priv->dbgfs->sram_len);
@@ -159,9 +168,9 @@ static ssize_t iwl_dbgfs_sram_read(struct file *file,
                                 break;
                         }
                 }
-                pos += sprintf(buf+pos, "0x%08x ", val);
+                pos += scnprintf(buf + pos, bufsz - pos, "0x%08x ", val);
         }
-        pos += sprintf(buf+pos, "\n");
+        pos += scnprintf(buf + pos, bufsz - pos, "\n");
         iwl_release_nic_access(priv);
 
         ret = simple_read_from_buffer(user_buf, count, ppos, buf, pos);
@@ -210,44 +219,50 @@ static ssize_t iwl_dbgfs_stations_read(struct file *file, char __user *user_buf,
         if(!buf)
                 return -ENOMEM;
 
-        pos += sprintf(buf+pos, "num of stations: %d\n\n",
+        pos += scnprintf(buf + pos, bufsz - pos, "num of stations: %d\n\n",
                         priv->num_stations);
 
         for (i = 0; i < max_sta; i++) {
                 station = &priv->stations[i];
                 if (station->used) {
-                        pos += sprintf(buf+pos, "station %d:\ngeneral data:\n",
-                                        i+1);
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                        "station %d:\ngeneral data:\n", i+1);
                         print_mac(mac, station->sta.sta.addr);
-                        pos += sprintf(buf+pos, "id: %u\n",
+                        pos += scnprintf(buf + pos, bufsz - pos, "id: %u\n",
                                         station->sta.sta.sta_id);
-                        pos += sprintf(buf+pos, "mode: %u\n",
+                        pos += scnprintf(buf + pos, bufsz - pos, "mode: %u\n",
                                         station->sta.mode);
-                        pos += sprintf(buf+pos, "flags: 0x%x\n",
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                        "flags: 0x%x\n",
                                         station->sta.station_flags_msk);
-                        pos += sprintf(buf+pos, "ps_status: %u\n",
-                                        station->ps_status);
-
-                        pos += sprintf(buf+pos, "tid data:\n");
-
-                        pos += sprintf(buf+pos, "seq_num\t\ttxq_id\t");
-                        pos += sprintf(buf+pos, "frame_count\twait_for_ba\t");
-                        pos += sprintf(buf+pos, "start_idx\tbitmap0\t");
-                        pos += sprintf(buf+pos, "bitmap1\trate_n_flags\n");
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                        "ps_status: %u\n", station->ps_status);
+                        pos += scnprintf(buf + pos, bufsz - pos, "tid data:\n");
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                        "seq_num\t\ttxq_id\t");
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                        "frame_count\twait_for_ba\t");
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                        "start_idx\tbitmap0\t");
+                        pos += scnprintf(buf + pos, bufsz - pos,
+                                        "bitmap1\trate_n_flags\n");
 
                         for (j = 0; j < MAX_TID_COUNT; j++) {
-                                pos += sprintf(buf+pos, "[%d]:\t\t%u\t",
-                                                j, station->tid[j].seq_number);
-                                pos += sprintf(buf+pos, "%u\t\t%u\t\t%u\t\t",
+                                pos += scnprintf(buf + pos, bufsz - pos,
+                                                "[%d]:\t\t%u\t", j,
+                                                station->tid[j].seq_number);
+                                pos += scnprintf(buf + pos, bufsz - pos,
+                                                "%u\t\t%u\t\t%u\t\t",
                                                 station->tid[j].agg.txq_id,
                                                 station->tid[j].agg.frame_count,
                                                 station->tid[j].agg.wait_for_ba);
-                                pos += sprintf(buf+pos, "%u\t%llu\t%u\n",
+                                pos += scnprintf(buf + pos, bufsz - pos,
+                                                "%u\t%llu\t%u\n",
                                                 station->tid[j].agg.start_idx,
                                                 (unsigned long long)station->tid[j].agg.bitmap,
                                                 station->tid[j].agg.rate_n_flags);
                         }
-                        pos += sprintf(buf+pos, "\n");
+                        pos += scnprintf(buf + pos, bufsz - pos, "\n");
                 }
         }