Messages in this thread Patch in this message | | | From | Neal Cardwell <> | Date | Mon, 28 Jun 2021 13:09:43 -0400 | Subject | Re: [PATCH] tcp: Do not reset the icsk_ca_initialized in tcp_init_transfer. |
| |
On Mon, Jun 28, 2021 at 11:39 AM Nguyen Dinh Phi <phind.uet@gmail.com> wrote: > > icsk_ca_initialized be always set to zero before we examine it in if > block, this makes the congestion control module's initialization be > called even if the CC module was initialized already. > In case the CC module allocates and setups its dynamically allocated > private data in its init() function, e.g, CDG, the memory leak may occur. > > Reported-by: syzbot+f1e24a0594d4e3a895d3@syzkaller.appspotmail.com > > Signed-off-by: Nguyen Dinh Phi <phind.uet@gmail.com> > --- > net/ipv4/tcp_input.c | 1 - > 1 file changed, 1 deletion(-) > > diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c > index 7d5e59f688de..855ada2be25e 100644 > --- a/net/ipv4/tcp_input.c > +++ b/net/ipv4/tcp_input.c > @@ -5922,7 +5922,6 @@ void tcp_init_transfer(struct sock *sk, int bpf_op, struct sk_buff *skb) > tp->snd_cwnd = tcp_init_cwnd(tp, __sk_dst_get(sk)); > tp->snd_cwnd_stamp = tcp_jiffies32; > > - icsk->icsk_ca_initialized = 0;
If this patch removes that line, then AFAICT the patch should also insert a corresponding:
icsk->icsk_ca_initialized = 0;
in tcp_ca_openreq_child(), so that any non-zero icsk_ca_initialized value in a listener socket (on which setsockopt(TCP_CONGESTION) was called) is not erroneously inherited by a child socket due to the tcp_create_openreq_child() -> inet_csk_clone_lock() -> sock_copy() call chain. Something like:
diff --git a/net/ipv4/tcp_minisocks.c b/net/ipv4/tcp_minisocks.c index c48d8336f26d..4d6a76dfa1c4 100644 --- a/net/ipv4/tcp_minisocks.c +++ b/net/ipv4/tcp_minisocks.c @@ -446,6 +446,7 @@ void tcp_ca_openreq_child(struct sock *sk, const struct dst_entry *dst) }
/* If no valid choice made yet, assign current system default ca. */ + icsk->icsk_ca_initialized = 0; if (!ca_got_dst && (!icsk->icsk_ca_setsockopt || !bpf_try_module_get(icsk->icsk_ca_ops, icsk->icsk_ca_ops->owner))) thanks, neal
| |