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authorLuiz Augusto von Dentz <luiz.von.dentz@intel.com>2023-04-06 19:33:09 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2023-04-20 13:10:25 +0300
commitd9ba36c22a7bb09d6bac4cc2f243eff05da53f43 (patch)
tree1dc4a008c46320efdc50ff2b47d8547dd5c09736 /net/bluetooth
parent8533fe864574c4fbaf62d1bc392929a025df122a (diff)
downloadlinux-d9ba36c22a7bb09d6bac4cc2f243eff05da53f43.tar.xz
Bluetooth: L2CAP: Fix use-after-free in l2cap_disconnect_{req,rsp}
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@kernel.org Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Min Li <lm0963hack@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'net/bluetooth')
-rw-r--r--net/bluetooth/l2cap_core.c24
1 files changed, 6 insertions, 18 deletions
diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c
index 367b1dec2e75..f9d2ce9cee36 100644
--- a/net/bluetooth/l2cap_core.c
+++ b/net/bluetooth/l2cap_core.c
@@ -4647,33 +4647,27 @@ static inline int l2cap_disconnect_req(struct l2cap_conn *conn,
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;
}
@@ -4693,33 +4687,27 @@ static inline int l2cap_disconnect_rsp(struct l2cap_conn *conn,
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;
}