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cxgb4: memory corruption in debugfs

PATCH Applied Dan Carpenter 3 participants 4 messages Aug 18, 2015 – Aug 19, 2015

Subsystems (4)
Networking Network drivers Kernel janitors CXGB4 Ethernet driver (CXGB4)
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Dan Carpenter

author
#0 lore raw

PATCH 1/1 cxgb4: memory corruption in debugfs

You can't use kstrtoul() with an int or it causes memory corruption. Also j should be unsigned or we have underflow bugs.

I considered changing "j" to unsigned long but everything fits in a u32.

Fixes 8e3d04fd7d70 ('cxgb4: Add MPS tracing support')
Signed-off-by Dan Carpenter <[email protected]>
drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c +6 -5
index 1732e29..0a87a32 100644
@@ -1289,13 +1289,14 @@ static unsigned int xdigit2int(unsigned char c)
 static ssize_t mps_trc_write(struct file *file, const char __user *buf,
 			     size_t count, loff_t *pos)
 {
-	int i, j, enable, ret;
+	int i, enable, ret;
 	u32 *data, *mask;
 	struct trace_params tp;
 	const struct inode *ino;
 	unsigned int trcidx;
 	char *s, *p, *word, *end;
 	struct adapter *adap;
+	u32 j;
 
 	ino = file_inode(file);
 	trcidx = (uintptr_t)ino->i_private & 3;

@@ -1340,7 +1341,7 @@ static ssize_t mps_trc_write(struct file *file, const char __user *buf,
 
 		if (!strncmp(word, "qid=", 4)) {
 			end = (char *)word + 4;
-			ret = kstrtoul(end, 10, (unsigned long *)&j);
+			ret = kstrtouint(end, 10, &j);
 			if (ret)
 				goto out;
 			if (!adap->trace_rss) {

@@ -1369,7 +1370,7 @@ static ssize_t mps_trc_write(struct file *file, const char __user *buf,
 		}
 		if (!strncmp(word, "snaplen=", 8)) {
 			end = (char *)word + 8;
-			ret = kstrtoul(end, 10, (unsigned long *)&j);
+			ret = kstrtouint(end, 10, &j);
 			if (ret || j > 9600) {
 inval:				count = -EINVAL;
 				goto out;

@@ -1379,7 +1380,7 @@ inval:				count = -EINVAL;
 		}
 		if (!strncmp(word, "minlen=", 7)) {
 			end = (char *)word + 7;
-			ret = kstrtoul(end, 10, (unsigned long *)&j);
+			ret = kstrtouint(end, 10, &j);
 			if (ret || j > TFMINPKTSIZE_M)
 				goto inval;
 			tp.min_len = j;

@@ -1453,7 +1454,7 @@ inval:				count = -EINVAL;
 		}
 		if (*word = '@') {
 			end = (char *)word + 1;
-			ret = kstrtoul(end, 10, (unsigned long *)&j);
+			ret = kstrtouint(end, 10, &j);
 			if (*end && *end != '\n')
 				goto inval;
 			if (j & 7)          /* doesn't start at multiple of 8 */
#1 lore raw
Quoted 4 lines · Dan Carpenter

You can't use kstrtoul() with an int or it causes memory corruption. Also j should be unsigned or we have underflow bugs.

I considered changing "j" to unsigned long but everything fits in a u32.

Excuse me, but kstrtouint()'s last argument is not "u32 *" but "unsigned int *". Aren't there architectures where sizeof(unsigned int) > sizeof(u32) ?

Quoted 33 lines
Fixes 8e3d04fd7d70 ('cxgb4: Add MPS tracing support')
Signed-off-by Dan Carpenter <[email protected]>
drivers/net/ethernet/chelsio/cxgb4/cxgb4_debugfs.c +3 -2
index 1732e29..0a87a32 100644
@@ -1289,13 +1289,14 @@ static unsigned int xdigit2int(unsigned char c)
 static ssize_t mps_trc_write(struct file *file, const char __user *buf,
 			     size_t count, loff_t *pos)
 {
-	int i, j, enable, ret;
+	int i, enable, ret;
 	u32 *data, *mask;
 	struct trace_params tp;
 	const struct inode *ino;
 	unsigned int trcidx;
 	char *s, *p, *word, *end;
 	struct adapter *adap;
+	u32 j;
 
 	ino = file_inode(file);
 	trcidx = (uintptr_t)ino->i_private & 3;

@@ -1340,7 +1341,7 @@ static ssize_t mps_trc_write(struct file *file, const char __user *buf,
 
 		if (!strncmp(word, "qid=", 4)) {
 			end = (char *)word + 4;
-			ret = kstrtoul(end, 10, (unsigned long *)&j);
+			ret = kstrtouint(end, 10, &j);
 			if (ret)
 				goto out;
 			if (!adap->trace_rss) {
author
#2 lore raw
Quoted 8 lines · Tetsuo Handa
Quoted 4 lines · Dan Carpenter

You can't use kstrtoul() with an int or it causes memory corruption. Also j should be unsigned or we have underflow bugs.

I considered changing "j" to unsigned long but everything fits in a u32.

Excuse me, but kstrtouint()'s last argument is not "u32 *" but "unsigned int *". Aren't there architectures where sizeof(unsigned int) > sizeof(u32) ?

No.

regards,
dan carpenter

maintainer Applied
#3 lore raw
In reply to Dan Carpenter

From: Dan Carpenter <[email protected]>
Date: Tue, 18 Aug 2015 12:31:44 +0300

Quoted 7 lines

You can't use kstrtoul() with an int or it causes memory corruption. Also j should be unsigned or we have underflow bugs.

I considered changing "j" to unsigned long but everything fits in a u32.

Fixes 8e3d04fd7d70 ('cxgb4: Add MPS tracing support')
Signed-off-by Dan Carpenter <[email protected]>

Applied, thanks Dan.