[PATCH 05/14] Bluetooth: RFCOMM - Fix info leak in getsockopt(BT_SECURITY)

From: Mathias Krause
Date: Wed Aug 15 2012 - 17:36:49 EST


The RFCOMM code fails to initialize the key_size member of struct
bt_security before copying it to userland -- that for leaking one
byte kernel stack. Initialize key_size with 0 to avoid the info
leak.

Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Cc: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Cc: Gustavo Padovan <gustavo@xxxxxxxxxxx>
Cc: Johan Hedberg <johan.hedberg@xxxxxxxxx>
---
net/bluetooth/rfcomm/sock.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index 7e1e596..64f55ca 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -822,6 +822,7 @@ static int rfcomm_sock_getsockopt(struct socket *sock, int level, int optname, c
}

sec.level = rfcomm_pi(sk)->sec_level;
+ sec.key_size = 0;

len = min_t(unsigned int, len, sizeof(sec));
if (copy_to_user(optval, (char *) &sec, len))
--
1.7.10.4

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