| Message ID | 20241014153808.51894-3-ignat@cloudflare.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | do not leave dangling sk pointers in pf->create functions | expand |
From: Ignat Korchagin <ignat@cloudflare.com> Date: Mon, 14 Oct 2024 16:38:01 +0100 > bt_sock_alloc() allocates the sk object and attaches it to the provided > sock object. On error l2cap_sock_alloc() frees the sk object, but the > dangling pointer is still attached to the sock object, which may create > use-after-free in other code. > > Signed-off-by: Ignat Korchagin <ignat@cloudflare.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Checked all bt_sock_alloc() paths and confirmed only rfcomm and l2cap need changes.
On Mon, Oct 14, 2024 at 11:23 PM Kuniyuki Iwashima <kuniyu@amazon.com> wrote: > > From: Ignat Korchagin <ignat@cloudflare.com> > Date: Mon, 14 Oct 2024 16:38:01 +0100 > > bt_sock_alloc() allocates the sk object and attaches it to the provided > > sock object. On error l2cap_sock_alloc() frees the sk object, but the > > dangling pointer is still attached to the sock object, which may create > > use-after-free in other code. > > > > Signed-off-by: Ignat Korchagin <ignat@cloudflare.com> > > Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> > > Checked all bt_sock_alloc() paths and confirmed only rfcomm and l2cap > need changes. Reviewed-by: Eric Dumazet <edumazet@google.com>
diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c index ba437c6f6ee5..18e89e764f3b 100644 --- a/net/bluetooth/l2cap_sock.c +++ b/net/bluetooth/l2cap_sock.c @@ -1886,6 +1886,7 @@ static struct sock *l2cap_sock_alloc(struct net *net, struct socket *sock, chan = l2cap_chan_create(); if (!chan) { sk_free(sk); + sock->sk = NULL; return NULL; }
bt_sock_alloc() allocates the sk object and attaches it to the provided sock object. On error l2cap_sock_alloc() frees the sk object, but the dangling pointer is still attached to the sock object, which may create use-after-free in other code. Signed-off-by: Ignat Korchagin <ignat@cloudflare.com> --- net/bluetooth/l2cap_sock.c | 1 + 1 file changed, 1 insertion(+)