diff options
| author | Paolo Abeni <pabeni@redhat.com> | 2023-12-04 17:08:05 +0100 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2023-12-06 05:07:02 +0100 |
| commit | 58d3aade20cdddbac6c9707ac0f3f5f8c1278b74 (patch) | |
| tree | cb236954a4b2b7a6db71e238163a273bfc3ae8fb /include | |
| parent | net: bnxt: fix a potential use-after-free in bnxt_init_tc (diff) | |
| download | linux-58d3aade20cdddbac6c9707ac0f3f5f8c1278b74.tar.xz linux-58d3aade20cdddbac6c9707ac0f3f5f8c1278b74.zip | |
tcp: fix mid stream window clamp.
After the blamed commit below, if the user-space application performs
window clamping when tp->rcv_wnd is 0, the TCP socket will never be
able to announce a non 0 receive window, even after completely emptying
the receive buffer and re-setting the window clamp to higher values.
Refactor tcp_set_window_clamp() to address the issue: when the user
decreases the current clamp value, set rcv_ssthresh according to the
same logic used at buffer initialization, but ensuring reserved mem
provisioning.
To avoid code duplication factor-out the relevant bits from
tcp_adjust_rcv_ssthresh() in a new helper and reuse it in the above
scenario.
When increasing the clamp value, give the rcv_ssthresh a chance to grow
according to previously implemented heuristic.
Fixes: 3aa7857fe1d7 ("tcp: enable mid stream window clamp")
Reported-by: David Gibson <david@gibson.dropbear.id.au>
Reported-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/705dad54e6e6e9a010e571bf58e0b35a8ae70503.1701706073.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/net/tcp.h | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/include/net/tcp.h b/include/net/tcp.h index d2f0736b76b8..144ba48bb07b 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -1514,17 +1514,22 @@ static inline int tcp_full_space(const struct sock *sk) return tcp_win_from_space(sk, READ_ONCE(sk->sk_rcvbuf)); } -static inline void tcp_adjust_rcv_ssthresh(struct sock *sk) +static inline void __tcp_adjust_rcv_ssthresh(struct sock *sk, u32 new_ssthresh) { int unused_mem = sk_unused_reserved_mem(sk); struct tcp_sock *tp = tcp_sk(sk); - tp->rcv_ssthresh = min(tp->rcv_ssthresh, 4U * tp->advmss); + tp->rcv_ssthresh = min(tp->rcv_ssthresh, new_ssthresh); if (unused_mem) tp->rcv_ssthresh = max_t(u32, tp->rcv_ssthresh, tcp_win_from_space(sk, unused_mem)); } +static inline void tcp_adjust_rcv_ssthresh(struct sock *sk) +{ + __tcp_adjust_rcv_ssthresh(sk, 4U * tcp_sk(sk)->advmss); +} + void tcp_cleanup_rbuf(struct sock *sk, int copied); void __tcp_cleanup_rbuf(struct sock *sk, int copied); |