diff mbox series

[SRU,F,2/5] Bluetooth: RFCOMM: Fix not validating setsockopt user input

Message ID 20241028075902.114546-7-koichiro.den@canonical.com
State New
Headers show
Series None | expand

Commit Message

Koichiro Den Oct. 28, 2024, 7:58 a.m. UTC 
From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

[ Upstream commit a97de7bff13b1cc825c1b1344eaed8d6c2d3e695 ]

syzbot reported rfcomm_sock_setsockopt_old() is copying data without
checking user input length.

BUG: KASAN: slab-out-of-bounds in copy_from_sockptr_offset
include/linux/sockptr.h:49 [inline]
BUG: KASAN: slab-out-of-bounds in copy_from_sockptr
include/linux/sockptr.h:55 [inline]
BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt_old
net/bluetooth/rfcomm/sock.c:632 [inline]
BUG: KASAN: slab-out-of-bounds in rfcomm_sock_setsockopt+0x893/0xa70
net/bluetooth/rfcomm/sock.c:673
Read of size 4 at addr ffff8880209a8bc3 by task syz-executor632/5064

Fixes: 9f2c8a03fbb3 ("Bluetooth: Replace RFCOMM link mode with security level")
Fixes: bb23c0ab8246 ("Bluetooth: Add support for deferring RFCOMM connection setup")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(backported from commit eea40d33bf936a5c7fb03c190e61e0cfee00e872 linux-6.1.y)
[koichiroden: Use bt_copy_from_user instead of bt_copy_from_sockptr,
which was introduced in the preceding backport commit
"Bluetooth: SCO: Fix not validating setsockopt user input"]
CVE-2024-35966
Signed-off-by: Koichiro Den <koichiro.den@canonical.com>
---
 net/bluetooth/rfcomm/sock.c | 14 +++++---------
 1 file changed, 5 insertions(+), 9 deletions(-)
diff mbox series

Patch

diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
index e67310a749d2..21b895e780e3 100644
--- a/net/bluetooth/rfcomm/sock.c
+++ b/net/bluetooth/rfcomm/sock.c
@@ -633,7 +633,7 @@  static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname, char __u
 
 	switch (optname) {
 	case RFCOMM_LM:
-		if (get_user(opt, (u32 __user *) optval)) {
+		if (bt_copy_from_user(&opt, sizeof(opt), optval, optlen)) {
 			err = -EFAULT;
 			break;
 		}
@@ -667,7 +667,6 @@  static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname, c
 	struct sock *sk = sock->sk;
 	struct bt_security sec;
 	int err = 0;
-	size_t len;
 	u32 opt;
 
 	BT_DBG("sk %p", sk);
@@ -689,11 +688,9 @@  static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname, c
 
 		sec.level = BT_SECURITY_LOW;
 
-		len = min_t(unsigned int, sizeof(sec), optlen);
-		if (copy_from_user((char *) &sec, optval, len)) {
-			err = -EFAULT;
+		err = bt_copy_from_user(&sec, sizeof(sec), optval, optlen);
+		if (err)
 			break;
-		}
 
 		if (sec.level > BT_SECURITY_HIGH) {
 			err = -EINVAL;
@@ -709,10 +706,9 @@  static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname, c
 			break;
 		}
 
-		if (get_user(opt, (u32 __user *) optval)) {
-			err = -EFAULT;
+		err = bt_copy_from_user(&opt, sizeof(opt), optval, optlen);
+		if (err)
 			break;
-		}
 
 		if (opt)
 			set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);