This is a note to let you know that I've just added the patch titled Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: bluetooth-l2cap-fix-l2cap_global_chan_by_psm-regression.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 332f1795ca202489c665a75e62e18ff6284de077 Mon Sep 17 00:00:00 2001 From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> Date: Mon, 1 Aug 2022 13:52:07 -0700 Subject: Bluetooth: L2CAP: Fix l2cap_global_chan_by_psm regression From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> commit 332f1795ca202489c665a75e62e18ff6284de077 upstream. 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) Fixes: d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free caused by l2cap_chan_put") Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/bluetooth/l2cap_core.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -1804,11 +1804,11 @@ static struct l2cap_chan *l2cap_global_c 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; @@ -1827,11 +1827,10 @@ static struct l2cap_chan *l2cap_global_c dst_match = !bacmp(&c->dst, dst); if (src_match && dst_match) { c = l2cap_chan_hold_unless_zero(c); - if (!c) - continue; - - read_unlock(&chan_list_lock); - return c; + if (c) { + read_unlock(&chan_list_lock); + return c; + } } /* Closest match */ Patches currently in stable-queue which might be from luiz.von.dentz@xxxxxxxxx are queue-4.9/bluetooth-l2cap-fix-use-after-free-caused-by-l2cap_chan_put.patch queue-4.9/bluetooth-l2cap-fix-l2cap_global_chan_by_psm-regression.patch