Commit 4f0ce36d authored Aug 01, 2022 by Luiz Augusto von Dentz Committed by Lee Jones Nov 22, 2022

UPSTREAM: Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression



The patch d0be8347c623: "Bluetooth: L2CAP: Fix use-after-free caused
by l2cap_chan_put" from Jul 21, 2022, leads to the following Smatch
static checker warning:

        net/bluetooth/l2cap_core.c:1977 l2cap_global_chan_by_psm()
        error: we previously assumed 'c' could be null (see line 1996)

Bug: 254441685
Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
(cherry picked from commit 332f1795ca202489c665a75e62e18ff6284de077)
Signed-off-by: Lee Jones <joneslee@google.com>
Change-Id: I20b471b7348f5907427918792e77fa7543da51a4

parent 624ab3a0

net/bluetooth/l2cap_core.c

+6 −7

Original line number	Diff line number	Diff line
		@@ -1813,11 +1813,11 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
		bdaddr_t *dst,
		u8 link_type)
		{
		struct l2cap_chan c, c1 = NULL;
		struct l2cap_chan c, tmp, *c1 = NULL;

		read_lock(&chan_list_lock);

		list_for_each_entry(c, &chan_list, global_l) {
		list_for_each_entry_safe(c, tmp, &chan_list, global_l) {
		if (state && c->state != state)
		continue;

		@@ -1836,12 +1836,11 @@ static struct l2cap_chan *l2cap_global_chan_by_psm(int state, __le16 psm,
		dst_match = !bacmp(&c->dst, dst);
		if (src_match && dst_match) {
		c = l2cap_chan_hold_unless_zero(c);
		if (!c)
		continue;

		if (c) {
		read_unlock(&chan_list_lock);
		return c;
		}
		}

		/* Closest match */
		src_any = !bacmp(&c->src, BDADDR_ANY);