This is a note to let you know that I've just added the patch titled
Bluetooth: L2CAP: Fix use-after-free in l2cap_disconnect_{req,rsp}
to the 5.4-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-use-after-free-in-l2cap_disconnect_-req-rsp.patch
and it can be found in the queue-5.4 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From a2a9339e1c9deb7e1e079e12e27a0265aea8421a Mon Sep 17 00:00:00 2001
From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Date: Thu, 6 Apr 2023 09:33:09 -0700
Subject: Bluetooth: L2CAP: Fix use-after-free in l2cap_disconnect_{req,rsp}
From: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
commit a2a9339e1c9deb7e1e079e12e27a0265aea8421a upstream.
Similar to commit d0be8347c623 ("Bluetooth: L2CAP: Fix use-after-free
caused by l2cap_chan_put"), just use l2cap_chan_hold_unless_zero to
prevent referencing a channel that is about to be destroyed.
Cc: stable@xxxxxxxxxx
Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@xxxxxxxxx>
Signed-off-by: Min Li <lm0963hack@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/bluetooth/l2cap_core.c | 24 ++++++------------------
1 file changed, 6 insertions(+), 18 deletions(-)
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4368,33 +4368,27 @@ static inline int l2cap_disconnect_req(s
BT_DBG("scid 0x%4.4x dcid 0x%4.4x", scid, dcid);
- mutex_lock(&conn->chan_lock);
-
- chan = __l2cap_get_chan_by_scid(conn, dcid);
+ chan = l2cap_get_chan_by_scid(conn, dcid);
if (!chan) {
- mutex_unlock(&conn->chan_lock);
cmd_reject_invalid_cid(conn, cmd->ident, dcid, scid);
return 0;
}
- l2cap_chan_hold(chan);
- l2cap_chan_lock(chan);
-
rsp.dcid = cpu_to_le16(chan->scid);
rsp.scid = cpu_to_le16(chan->dcid);
l2cap_send_cmd(conn, cmd->ident, L2CAP_DISCONN_RSP, sizeof(rsp), &rsp);
chan->ops->set_shutdown(chan);
+ mutex_lock(&conn->chan_lock);
l2cap_chan_del(chan, ECONNRESET);
+ mutex_unlock(&conn->chan_lock);
chan->ops->close(chan);
l2cap_chan_unlock(chan);
l2cap_chan_put(chan);
- mutex_unlock(&conn->chan_lock);
-
return 0;
}
@@ -4414,33 +4408,27 @@ static inline int l2cap_disconnect_rsp(s
BT_DBG("dcid 0x%4.4x scid 0x%4.4x", dcid, scid);
- mutex_lock(&conn->chan_lock);
-
- chan = __l2cap_get_chan_by_scid(conn, scid);
+ chan = l2cap_get_chan_by_scid(conn, scid);
if (!chan) {
mutex_unlock(&conn->chan_lock);
return 0;
}
- l2cap_chan_hold(chan);
- l2cap_chan_lock(chan);
-
if (chan->state != BT_DISCONN) {
l2cap_chan_unlock(chan);
l2cap_chan_put(chan);
- mutex_unlock(&conn->chan_lock);
return 0;
}
+ mutex_lock(&conn->chan_lock);
l2cap_chan_del(chan, 0);
+ mutex_unlock(&conn->chan_lock);
chan->ops->close(chan);
l2cap_chan_unlock(chan);
l2cap_chan_put(chan);
- mutex_unlock(&conn->chan_lock);
-
return 0;
}
Patches currently in stable-queue which might be from luiz.von.dentz@xxxxxxxxx are
queue-5.4/bluetooth-l2cap-fix-use-after-free-in-l2cap_disconnect_-req-rsp.patch
queue-5.4/bluetooth-fix-race-condition-in-hidp_session_thread.patch
