diff mbox

[v3,3/3] batman-adv: Only write requested number of byte to user buffer

Message ID 1323527316-15071-3-git-send-email-sven@narfation.org (mailing list archive)
State Superseded, archived
Commit d22e13c6c380261cf0b13d34e6412a1e393b5197
Headers

Commit Message

Sven Eckelmann Dec. 10, 2011, 2:28 p.m. UTC 
  Don't write more than the requested number of bytes of an batman-adv icmp
packet to the userspace buffer. Otherwise unrelated userspace memory might get
overridden by the kernel.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 icmp_socket.c |    5 ++---
 1 files changed, 2 insertions(+), 3 deletions(-)

Comments

Marek Lindner Dec. 12, 2011, 10:48 a.m. UTC | #1 
On Saturday, December 10, 2011 22:28:36 Sven Eckelmann wrote:
> Don't write more than the requested number of bytes of an batman-adv icmp
> packet to the userspace buffer. Otherwise unrelated userspace memory might
> get overridden by the kernel.

Applied in revision d22e13c.

Thanks,
Marek
diff mbox

Patch

diff --git a/icmp_socket.c b/icmp_socket.c
index 4dc55e8..5d69e10 100644
--- a/icmp_socket.c
+++ b/icmp_socket.c
@@ -136,10 +136,9 @@  static ssize_t bat_socket_read(struct file *file, char __user *buf,
 
 	spin_unlock_bh(&socket_client->lock);
 
-	error = copy_to_user(buf, &socket_packet->icmp_packet,
-			     socket_packet->icmp_len);
+	packet_len = min(count, socket_packet->icmp_len);
+	error = copy_to_user(buf, &socket_packet->icmp_packet, packet_len);
 
-	packet_len = socket_packet->icmp_len;
 	kfree(socket_packet);
 
 	if (error)