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| author | Hillf Danton <hdanton@sina.com> | 2020-02-05 10:31:59 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-01 13:14:32 +0200 |
| commit | 4b0795d5b615de48541eae1a87b5a37543e1c17f (patch) | |
| tree | b393b5a3a5b90492ec4fdd64568e6003eef02462 | |
| parent | f9cb6b6124ac3e1586251329e51b898f1d0a54e6 (diff) | |
| download | linux-stable-4b0795d5b615de48541eae1a87b5a37543e1c17f.tar.gz linux-stable-4b0795d5b615de48541eae1a87b5a37543e1c17f.tar.bz2 linux-stable-4b0795d5b615de48541eae1a87b5a37543e1c17f.zip | |
Bluetooth: prefetch channel before killing sock
[ Upstream commit 2a154903cec20fb64ff4d7d617ca53c16f8fd53a ]
Prefetch channel before killing sock in order to fix UAF like
BUG: KASAN: use-after-free in l2cap_sock_release+0x24c/0x290 net/bluetooth/l2cap_sock.c:1212
Read of size 8 at addr ffff8880944904a0 by task syz-fuzzer/9751
Reported-by: syzbot+c3c5bdea7863886115dc@syzkaller.appspotmail.com
Fixes: 6c08fc896b60 ("Bluetooth: Fix refcount use-after-free issue")
Cc: Manish Mandlik <mmandlik@google.com>
Signed-off-by: Hillf Danton <hdanton@sina.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/bluetooth/l2cap_sock.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index d128750e4730..5572042f0453 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1190,6 +1190,7 @@ static int l2cap_sock_release(struct socket *sock) { struct sock *sk = sock->sk; int err; + struct l2cap_chan *chan; BT_DBG("sock %p, sk %p", sock, sk); @@ -1199,15 +1200,16 @@ static int l2cap_sock_release(struct socket *sock) bt_sock_unlink(&l2cap_sk_list, sk); err = l2cap_sock_shutdown(sock, 2); + chan = l2cap_pi(sk)->chan; - l2cap_chan_hold(l2cap_pi(sk)->chan); - l2cap_chan_lock(l2cap_pi(sk)->chan); + l2cap_chan_hold(chan); + l2cap_chan_lock(chan); sock_orphan(sk); l2cap_sock_kill(sk); - l2cap_chan_unlock(l2cap_pi(sk)->chan); - l2cap_chan_put(l2cap_pi(sk)->chan); + l2cap_chan_unlock(chan); + l2cap_chan_put(chan); return err; } |