i40e: fix use of untrusted scalar value warning

This is a fix for an issue reported by coverity, reported by
Hannes Frederic Sowa.

I'm unable to test if this patch actually fixes the coverity
reported issue, feedback is welcome.

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
CC: Hannes Frederic Sowa <hannes@stressinduktion.org>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

1 files changed, 18 insertions, 16 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
index c80fcb4d8ff8..387bf94495f0 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_debugfs.c
@@ -151,9 +151,7 @@ static ssize_t i40e_dbg_dump_write(struct file *filp,
                                    size_t count, loff_t *ppos)
 {
         struct i40e_pf *pf = filp->private_data;
-        char dump_request_buf[16];
         bool seid_found = false;
-        int bytes_not_copied;
         long seid = -1;
         int buflen = 0;
         int i, ret;
@@ -163,21 +161,12 @@ static ssize_t i40e_dbg_dump_write(struct file *filp,
         /* don't allow partial writes */
         if (*ppos != 0)
                 return 0;
-        if (count >= sizeof(dump_request_buf))
-                return -ENOSPC;
-
-        bytes_not_copied = copy_from_user(dump_request_buf, buffer, count);
-        if (bytes_not_copied < 0)
-                return bytes_not_copied;
-        if (bytes_not_copied > 0)
-                count -= bytes_not_copied;
-        dump_request_buf[count] = '\0';
 
         /* decode the SEID given to be dumped */
-        ret = kstrtol(dump_request_buf, 0, &seid);
-        if (ret < 0) {
-                dev_info(&pf->pdev->dev, "bad seid value '%s'\n",
-                         dump_request_buf);
+        ret = kstrtol_from_user(buffer, count, 0, &seid);
+
+        if (ret) {
+                dev_info(&pf->pdev->dev, "bad seid value\n");
         } else if (seid == 0) {
                 seid_found = true;
 
@@ -1023,11 +1012,11 @@ static ssize_t i40e_dbg_command_write(struct file *filp,
                                       size_t count, loff_t *ppos)
 {
         struct i40e_pf *pf = filp->private_data;
+        char *cmd_buf, *cmd_buf_tmp;
         int bytes_not_copied;
         struct i40e_vsi *vsi;
         u8 *print_buf_start;
         u8 *print_buf;
-        char *cmd_buf;
         int vsi_seid;
         int veb_seid;
         int cnt;
@@ -1046,6 +1035,12 @@ static ssize_t i40e_dbg_command_write(struct file *filp,
                 count -= bytes_not_copied;
         cmd_buf[count] = '\0';
 
+        cmd_buf_tmp = strchr(cmd_buf, '\n');
+        if (cmd_buf_tmp) {
+                *cmd_buf_tmp = '\0';
+                count = cmd_buf_tmp - cmd_buf + 1;
+        }
+
         print_buf_start = kzalloc(I40E_MAX_DEBUG_OUT_BUFFER, GFP_KERNEL);
         if (!print_buf_start)
                 goto command_write_done;
@@ -1900,6 +1895,7 @@ static ssize_t i40e_dbg_netdev_ops_write(struct file *filp,
         struct i40e_pf *pf = filp->private_data;
         int bytes_not_copied;
         struct i40e_vsi *vsi;
+        char *buf_tmp;
         int vsi_seid;
         int i, cnt;
 
@@ -1918,6 +1914,12 @@ static ssize_t i40e_dbg_netdev_ops_write(struct file *filp,
                 count -= bytes_not_copied;
         i40e_dbg_netdev_ops_buf[count] = '\0';
 
+        buf_tmp = strchr(i40e_dbg_netdev_ops_buf, '\n');
+        if (buf_tmp) {
+                *buf_tmp = '\0';
+                count = buf_tmp - i40e_dbg_netdev_ops_buf + 1;
+        }
+
         if (strncmp(i40e_dbg_netdev_ops_buf, "tx_timeout", 10) == 0) {
                 cnt = sscanf(&i40e_dbg_netdev_ops_buf[11], "%i", &vsi_seid);
                 if (cnt != 1) {