From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Date: Fri, 29 Jul 2022 18:03:27 +0000 (-0700)
Subject: Bluetooth: ISO: Fix memory corruption
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=b4443423278263d229dbeee12d09e657b78d64ab;p=linux.git
Bluetooth: ISO: Fix memory corruption
The following memory corruption can happen since iso_pinfo.base size
did not account for its headers (4 bytes):
net/bluetooth/eir.c
76 memcpy(&eir[eir_len], data, data_len);
^^^^^^^ ^^^^^^^^
77 eir_len += data_len;
78
79 return eir_len;
80 }
The "eir" buffer has 252 bytes and data_len is 252 but we do a memcpy()
to &eir[4] so this can corrupt 4 bytes beyond the end of the buffer.
Fixes: f764a6c2c1e4 ("Bluetooth: ISO: Add broadcast support")
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
---
diff --git a/net/bluetooth/iso.c b/net/bluetooth/iso.c
index dded22cde0d17..70c2dd30cb136 100644
--- a/net/bluetooth/iso.c
+++ b/net/bluetooth/iso.c
@@ -44,6 +44,9 @@ static void iso_sock_kill(struct sock *sk);
/* ----- ISO socket info ----- */
#define iso_pi(sk) ((struct iso_pinfo *)sk)
+#define EIR_SERVICE_DATA_LENGTH 4
+#define BASE_MAX_LENGTH (HCI_MAX_PER_AD_LENGTH - EIR_SERVICE_DATA_LENGTH)
+
struct iso_pinfo {
struct bt_sock bt;
bdaddr_t src;
@@ -57,7 +60,7 @@ struct iso_pinfo {
__u32 flags;
struct bt_iso_qos qos;
__u8 base_len;
- __u8 base[HCI_MAX_PER_AD_LENGTH];
+ __u8 base[BASE_MAX_LENGTH];
struct iso_conn *conn;
};