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authorMarcel Holtmann <marcel@holtmann.org>2007-05-05 00:35:59 +0200
committerMarcel Holtmann <marcel@holtmann.org>2007-05-05 00:35:59 +0200
commit0878b6667f28772aa7d6b735abff53efc7bf6d91 (patch)
tree5a1dbfb35f679335fbec4cbd17dfe64926db7750 /net/bluetooth/l2cap.c
parentdc87c3985e9b442c60994308a96f887579addc39 (diff)
[Bluetooth] Fix L2CAP and HCI setsockopt() information leaks
The L2CAP and HCI setsockopt() implementations have a small information leak that makes it possible to leak kernel stack memory to userspace. If the optlen parameter is 0, no data will be copied by copy_from_user(), but the uninitialized stack buffer will be read and stored later. A call to getsockopt() can now retrieve the leaked information. To fix this problem the stack buffer given to copy_from_user() must be initialized with the current settings. Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Diffstat (limited to 'net/bluetooth/l2cap.c')
-rw-r--r--net/bluetooth/l2cap.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/net/bluetooth/l2cap.c b/net/bluetooth/l2cap.c
index a5867879b61..a59b1fb63b7 100644
--- a/net/bluetooth/l2cap.c
+++ b/net/bluetooth/l2cap.c
@@ -954,11 +954,17 @@ static int l2cap_sock_setsockopt(struct socket *sock, int level, int optname, ch
switch (optname) {
case L2CAP_OPTIONS:
+ opts.imtu = l2cap_pi(sk)->imtu;
+ opts.omtu = l2cap_pi(sk)->omtu;
+ opts.flush_to = l2cap_pi(sk)->flush_to;
+ opts.mode = 0x00;
+
len = min_t(unsigned int, sizeof(opts), optlen);
if (copy_from_user((char *) &opts, optval, len)) {
err = -EFAULT;
break;
}
+
l2cap_pi(sk)->imtu = opts.imtu;
l2cap_pi(sk)->omtu = opts.omtu;
break;