kernel/*: switch to memdup_user_nul()

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

1 files changed, 28 insertions, 51 deletions

diff --git a/kernel/sysctl.c b/kernel/sysctl.c
index dc6858d6639e..5faf89ac9ec0 100644
--- a/kernel/sysctl.c
+++ b/kernel/sysctl.c
@@ -2047,9 +2047,8 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 		  void *data)
 {
 	int *i, vleft, first = 1, err = 0;
-	unsigned long page = 0;
 	size_t left;
-	char *kbuf;
+	char *kbuf = NULL, *p;
 	
 	if (!tbl_data || !table->maxlen || !*lenp || (*ppos && !write)) {
 		*lenp = 0;
@@ -2078,15 +2077,9 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			err = -EFAULT;
-			goto free;
-		}
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 	}
 
 	for (; left && vleft--; i++, first=0) {
@@ -2094,11 +2087,11 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 		bool neg;
 
 		if (write) {
-			left -= proc_skip_spaces(&kbuf);
+			left -= proc_skip_spaces(&p);
 
 			if (!left)
 				break;
-			err = proc_get_long(&kbuf, &left, &lval, &neg,
+			err = proc_get_long(&p, &left, &lval, &neg,
 					     proc_wspace_sep,
 					     sizeof(proc_wspace_sep), NULL);
 			if (err)
@@ -2125,10 +2118,9 @@ static int __do_proc_dointvec(void *tbl_data, struct ctl_table *table,
 	if (!write && !first && left && !err)
 		err = proc_put_char(&buffer, &left, '\n');
 	if (write && !err && left)
-		left -= proc_skip_spaces(&kbuf);
-free:
+		left -= proc_skip_spaces(&p);
 	if (write) {
-		free_page(page);
+		kfree(kbuf);
 		if (first)
 			return err ? : -EINVAL;
 	}
@@ -2310,9 +2302,8 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 {
 	unsigned long *i, *min, *max;
 	int vleft, first = 1, err = 0;
-	unsigned long page = 0;
 	size_t left;
-	char *kbuf;
+	char *kbuf = NULL, *p;
 
 	if (!data || !table->maxlen || !*lenp || (*ppos && !write)) {
 		*lenp = 0;
@@ -2340,15 +2331,9 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			err = -EFAULT;
-			goto free;
-		}
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 	}
 
 	for (; left && vleft--; i++, first = 0) {
@@ -2357,9 +2342,9 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 		if (write) {
 			bool neg;
 
-			left -= proc_skip_spaces(&kbuf);
+			left -= proc_skip_spaces(&p);
 
-			err = proc_get_long(&kbuf, &left, &val, &neg,
+			err = proc_get_long(&p, &left, &val, &neg,
 					     proc_wspace_sep,
 					     sizeof(proc_wspace_sep), NULL);
 			if (err)
@@ -2385,10 +2370,9 @@ static int __do_proc_doulongvec_minmax(void *data, struct ctl_table *table, int
 	if (!write && !first && left && !err)
 		err = proc_put_char(&buffer, &left, '\n');
 	if (write && !err)
-		left -= proc_skip_spaces(&kbuf);
-free:
+		left -= proc_skip_spaces(&p);
 	if (write) {
-		free_page(page);
+		kfree(kbuf);
 		if (first)
 			return err ? : -EINVAL;
 	}
@@ -2650,34 +2634,27 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 	}
 
 	if (write) {
-		unsigned long page = 0;
-		char *kbuf;
+		char *kbuf, *p;
 
 		if (left > PAGE_SIZE - 1)
 			left = PAGE_SIZE - 1;
 
-		page = __get_free_page(GFP_TEMPORARY);
-		kbuf = (char *) page;
-		if (!kbuf)
-			return -ENOMEM;
-		if (copy_from_user(kbuf, buffer, left)) {
-			free_page(page);
-			return -EFAULT;
-                }
-		kbuf[left] = 0;
+		p = kbuf = memdup_user_nul(buffer, left);
+		if (IS_ERR(kbuf))
+			return PTR_ERR(kbuf);
 
 		tmp_bitmap = kzalloc(BITS_TO_LONGS(bitmap_len) * sizeof(unsigned long),
 				     GFP_KERNEL);
 		if (!tmp_bitmap) {
-			free_page(page);
+			kfree(kbuf);
 			return -ENOMEM;
 		}
-		proc_skip_char(&kbuf, &left, '\n');
+		proc_skip_char(&p, &left, '\n');
 		while (!err && left) {
 			unsigned long val_a, val_b;
 			bool neg;
 
-			err = proc_get_long(&kbuf, &left, &val_a, &neg, tr_a,
+			err = proc_get_long(&p, &left, &val_a, &neg, tr_a,
 					     sizeof(tr_a), &c);
 			if (err)
 				break;
@@ -2688,12 +2665,12 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 
 			val_b = val_a;
 			if (left) {
-				kbuf++;
+				p++;
 				left--;
 			}
 
 			if (c == '-') {
-				err = proc_get_long(&kbuf, &left, &val_b,
+				err = proc_get_long(&p, &left, &val_b,
 						     &neg, tr_b, sizeof(tr_b),
 						     &c);
 				if (err)
@@ -2704,16 +2681,16 @@ int proc_do_large_bitmap(struct ctl_table *table, int write,
 					break;
 				}
 				if (left) {
-					kbuf++;
+					p++;
 					left--;
 				}
 			}
 
 			bitmap_set(tmp_bitmap, val_a, val_b - val_a + 1);
 			first = 0;
-			proc_skip_char(&kbuf, &left, '\n');
+			proc_skip_char(&p, &left, '\n');
 		}
-		free_page(page);
+		kfree(kbuf);
 	} else {
 		unsigned long bit_a, bit_b = 0;