convert a bunch of open-coded instances of memdup_user_nul()

A _lot_ of ->write() instances were open-coding it; some are
converted to memdup_user_nul(), a lot more remain...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

2 files changed, 35 insertions, 90 deletions

diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 94bd9e41c9ec..e249a66db533 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -497,14 +497,9 @@ static ssize_t smk_write_rules_list(struct file *file, const char __user *buf,
                 }
         }
 
-        data = kmalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(data, buf, count) != 0) {
-                rc = -EFAULT;
-                goto out;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
         /*
          * In case of parsing only part of user buf,
@@ -884,16 +879,10 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
             (count < SMK_CIPSOMIN || count > SMK_CIPSOMAX))
                 return -EINVAL;
 
-        data = kzalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(data, buf, count) != 0) {
-                rc = -EFAULT;
-                goto unlockedout;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
-        data[count] = '\0';
         rule = data;
         /*
          * Only allow one writer at a time. Writes should be
@@ -946,7 +935,6 @@ static ssize_t smk_set_cipso(struct file *file, const char __user *buf,
 
 out:
         mutex_unlock(&smack_cipso_lock);
-unlockedout:
         kfree(data);
         return rc;
 }
@@ -1187,14 +1175,9 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
         if (count < SMK_NETLBLADDRMIN)
                 return -EINVAL;
 
-        data = kzalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(data, buf, count) != 0) {
-                rc = -EFAULT;
-                goto free_data_out;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
         smack = kzalloc(count + 1, GFP_KERNEL);
         if (smack == NULL) {
@@ -1202,8 +1185,6 @@ static ssize_t smk_write_net4addr(struct file *file, const char __user *buf,
                 goto free_data_out;
         }
 
-        data[count] = '\0';
-
         rc = sscanf(data, "%hhd.%hhd.%hhd.%hhd/%u %s",
                 &host[0], &host[1], &host[2], &host[3], &masks, smack);
         if (rc != 6) {
@@ -1454,14 +1435,9 @@ static ssize_t smk_write_net6addr(struct file *file, const char __user *buf,
         if (count < SMK_NETLBLADDRMIN)
                 return -EINVAL;
 
-        data = kzalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(data, buf, count) != 0) {
-                rc = -EFAULT;
-                goto free_data_out;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
         smack = kzalloc(count + 1, GFP_KERNEL);
         if (smack == NULL) {
@@ -1469,8 +1445,6 @@ static ssize_t smk_write_net6addr(struct file *file, const char __user *buf,
                 goto free_data_out;
         }
 
-        data[count] = '\0';
-
         i = sscanf(data, "%x:%x:%x:%x:%x:%x:%x:%x/%u %s",
                         &scanned[0], &scanned[1], &scanned[2], &scanned[3],
                         &scanned[4], &scanned[5], &scanned[6], &scanned[7],
@@ -1865,14 +1839,9 @@ static ssize_t smk_write_ambient(struct file *file, const char __user *buf,
         if (!smack_privileged(CAP_MAC_ADMIN))
                 return -EPERM;
 
-        data = kzalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(data, buf, count) != 0) {
-                rc = -EFAULT;
-                goto out;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
         skp = smk_import_entry(data, count);
         if (IS_ERR(skp)) {
@@ -2041,14 +2010,9 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
         if (!smack_privileged(CAP_MAC_ADMIN))
                 return -EPERM;
 
-        data = kzalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(data, buf, count) != 0) {
-                kfree(data);
-                return -EFAULT;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
         rc = smk_parse_label_list(data, &list_tmp);
         kfree(data);
@@ -2133,14 +2097,9 @@ static ssize_t smk_write_unconfined(struct file *file, const char __user *buf,
         if (!smack_privileged(CAP_MAC_ADMIN))
                 return -EPERM;
 
-        data = kzalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(data, buf, count) != 0) {
-                rc = -EFAULT;
-                goto freeout;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
         /*
          * Clear the smack_unconfined on invalid label errors. This means
@@ -2696,19 +2655,15 @@ static ssize_t smk_write_syslog(struct file *file, const char __user *buf,
         if (!smack_privileged(CAP_MAC_ADMIN))
                 return -EPERM;
 
-        data = kzalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
-        if (copy_from_user(data, buf, count) != 0)
-                rc = -EFAULT;
-        else {
-                skp = smk_import_entry(data, count);
-                if (IS_ERR(skp))
-                        rc = PTR_ERR(skp);
-                else
-                        smack_syslog_label = skp;
-        }
+        skp = smk_import_entry(data, count);
+        if (IS_ERR(skp))
+                rc = PTR_ERR(skp);
+        else
+                smack_syslog_label = skp;
 
         kfree(data);
         return rc;
@@ -2798,14 +2753,9 @@ static ssize_t smk_write_relabel_self(struct file *file, const char __user *buf,
         if (*ppos != 0)
                 return -EINVAL;
 
-        data = kzalloc(count + 1, GFP_KERNEL);
-        if (data == NULL)
-                return -ENOMEM;
-
-        if (copy_from_user(data, buf, count) != 0) {
-                kfree(data);
-                return -EFAULT;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
 
         rc = smk_parse_label_list(data, &list_tmp);
         kfree(data);
diff --git a/security/tomoyo/securityfs_if.c b/security/tomoyo/securityfs_if.c
index 179a955b319d..06ab41b1ff28 100644
--- a/security/tomoyo/securityfs_if.c
+++ b/security/tomoyo/securityfs_if.c
@@ -43,13 +43,9 @@ static ssize_t tomoyo_write_self(struct file *file, const char __user *buf,
         int error;
         if (!count || count >= TOMOYO_EXEC_TMPSIZE - 10)
                 return -ENOMEM;
-        data = kzalloc(count + 1, GFP_NOFS);
-        if (!data)
-                return -ENOMEM;
-        if (copy_from_user(data, buf, count)) {
-                error = -EFAULT;
-                goto out;
-        }
+        data = memdup_user_nul(buf, count);
+        if (IS_ERR(data))
+                return PTR_ERR(data);
         tomoyo_normalize_line(data);
         if (tomoyo_correct_domain(data)) {
                 const int idx = tomoyo_read_lock();
@@ -87,7 +83,6 @@ static ssize_t tomoyo_write_self(struct file *file, const char __user *buf,
                 tomoyo_read_unlock(idx);
         } else
                 error = -EINVAL;
-out:
         kfree(data);
         return error ? error : count;
 }