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| author | Hillf Danton <hdanton@sina.com> | 2020-02-05 10:31:59 +0800 |
|---|---|---|
| committer | Marcel Holtmann <marcel@holtmann.org> | 2020-02-05 09:05:04 +0100 |
| commit | 2a154903cec20fb64ff4d7d617ca53c16f8fd53a (patch) | |
| tree | 7c1dfbe14f16ab556ffec7dccfd946816ca51415 /net/bluetooth/l2cap_sock.c | |
| parent | 89bd6147964ea3d72708ee30ba309ac675a5b997 (diff) | |
| download | linux-2a154903cec20fb64ff4d7d617ca53c16f8fd53a.tar.gz linux-2a154903cec20fb64ff4d7d617ca53c16f8fd53a.tar.bz2 linux-2a154903cec20fb64ff4d7d617ca53c16f8fd53a.zip | |
Bluetooth: prefetch channel before killing sock
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>
Diffstat (limited to 'net/bluetooth/l2cap_sock.c')
| -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 ab65304f3f63..390a9afab647 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1193,6 +1193,7 @@ 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); @@ -1202,15 +1203,16 @@ 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; } |