diff mbox series

[net-next,v3,07/10] net: pktgen: fix access outside of user given buffer in pktgen_thread_write()

Message ID 20250203170201.1661703-8-ps.report@gmx.net (mailing list archive)
State New
Headers show
Series Some pktgen fixes/improvments | expand

Commit Message

Peter Seiderer Feb. 3, 2025, 5:01 p.m. UTC
Honour the user given buffer size for the strn_len() calls (otherwise
strn_len() will access memory outside of the user given buffer).

Signed-off-by: Peter Seiderer <ps.report@gmx.net>
---
Changes v2 -> v3:
  - no changes

Changes v1 -> v2:
  - no changes
---
 net/core/pktgen.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

Comments

Simon Horman Feb. 4, 2025, 2:45 p.m. UTC | #1
On Mon, Feb 03, 2025 at 06:01:58PM +0100, Peter Seiderer wrote:
> Honour the user given buffer size for the strn_len() calls (otherwise
> strn_len() will access memory outside of the user given buffer).
> 
> Signed-off-by: Peter Seiderer <ps.report@gmx.net>

Reviewed-by: Simon Horman <horms@kernel.org>
diff mbox series

Patch

diff --git a/net/core/pktgen.c b/net/core/pktgen.c
index f6e35ba035c7..55064713223e 100644
--- a/net/core/pktgen.c
+++ b/net/core/pktgen.c
@@ -1900,8 +1900,8 @@  static ssize_t pktgen_thread_write(struct file *file,
 	i = len;
 
 	/* Read variable name */
-
-	len = strn_len(&user_buffer[i], sizeof(name) - 1);
+	max = min(sizeof(name) - 1, count - i);
+	len = strn_len(&user_buffer[i], max);
 	if (len < 0)
 		return len;
 
@@ -1931,7 +1931,8 @@  static ssize_t pktgen_thread_write(struct file *file,
 	if (!strcmp(name, "add_device")) {
 		char f[32];
 		memset(f, 0, 32);
-		len = strn_len(&user_buffer[i], sizeof(f) - 1);
+		max = min(sizeof(f) - 1, count - i);
+		len = strn_len(&user_buffer[i], max);
 		if (len < 0) {
 			ret = len;
 			goto out;