Commit 7c6d0edd authored Jun 14, 2024 by Luiz Augusto von Dentz Committed by Jinjiang Tu Jun 14, 2024

Bluetooth: RFCOMM: Fix not validating setsockopt user input

mainline inclusion
from mainline-v6.9-rc4
commit a97de7bff13b1cc825c1b1344eaed8d6c2d3e695
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I9QRFS
CVE: CVE-2024-35966

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=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: 9f2c8a03 ("Bluetooth: Replace RFCOMM link mode with security level")
Fixes: bb23c0ab ("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: Jinjiang Tu <tujinjiang@huawei.com>

parent 875b8b74

net/bluetooth/rfcomm/sock.c

+5 −9

Original line number	Diff line number	Diff line
		@@ -631,7 +631,7 @@ 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;
		}
		@@ -666,7 +666,6 @@ 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);
		@@ -688,11 +687,9 @@ 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;
		@@ -708,10 +705,9 @@ 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);