Bluetooth: RFCOMM: Fix not validating setsockopt user input

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: 9f2c8a03fb ("Bluetooth: Replace RFCOMM link mode with security level")
Fixes: bb23c0ab82 ("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>
This commit is contained in:
Luiz Augusto von Dentz 2024-04-05 15:43:45 -04:00
parent 51eda36d33
commit a97de7bff1
1 changed files with 5 additions and 9 deletions

View File

@ -629,7 +629,7 @@ static int rfcomm_sock_setsockopt_old(struct socket *sock, int optname,
switch (optname) {
case RFCOMM_LM:
if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
if (bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen)) {
err = -EFAULT;
break;
}
@ -664,7 +664,6 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
struct sock *sk = sock->sk;
struct bt_security sec;
int err = 0;
size_t len;
u32 opt;
BT_DBG("sk %p", sk);
@ -686,11 +685,9 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
sec.level = BT_SECURITY_LOW;
len = min_t(unsigned int, sizeof(sec), optlen);
if (copy_from_sockptr(&sec, optval, len)) {
err = -EFAULT;
err = bt_copy_from_sockptr(&sec, sizeof(sec), optval, optlen);
if (err)
break;
}
if (sec.level > BT_SECURITY_HIGH) {
err = -EINVAL;
@ -706,10 +703,9 @@ static int rfcomm_sock_setsockopt(struct socket *sock, int level, int optname,
break;
}
if (copy_from_sockptr(&opt, optval, sizeof(u32))) {
err = -EFAULT;
err = bt_copy_from_sockptr(&opt, sizeof(opt), optval, optlen);
if (err)
break;
}
if (opt)
set_bit(BT_SK_DEFER_SETUP, &bt_sk(sk)->flags);