diff options
| author | Eric Dumazet <edumazet@google.com> | 2022-02-01 10:46:40 -0800 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2022-02-02 16:22:37 -0800 |
| commit | b67985be400969578d4d4b17299714c0e5d2c07b (patch) | |
| tree | 68457fa31da2ea88566fab29049f5565aed425b7 /net/ipv4/tcp_input.c | |
| parent | 81eb8b0b18789e647e65579303529fd52d861cc2 (diff) | |
| download | linux-b67985be400969578d4d4b17299714c0e5d2c07b.tar.gz | |
tcp: add missing tcp_skb_can_collapse() test in tcp_shift_skb_data()
tcp_shift_skb_data() might collapse three packets into a larger one.
P_A, P_B, P_C -> P_ABC
Historically, it used a single tcp_skb_can_collapse_to(P_A) call,
because it was enough.
In commit 85712484110d ("tcp: coalesce/collapse must respect MPTCP extensions"),
this call was replaced by a call to tcp_skb_can_collapse(P_A, P_B)
But the now needed test over P_C has been missed.
This probably broke MPTCP.
Then later, commit 9b65b17db723 ("net: avoid double accounting for pure zerocopy skbs")
added an extra condition to tcp_skb_can_collapse(), but the missing call
from tcp_shift_skb_data() is also breaking TCP zerocopy, because P_A and P_C
might have different skb_zcopy_pure() status.
Fixes: 85712484110d ("tcp: coalesce/collapse must respect MPTCP extensions")
Fixes: 9b65b17db723 ("net: avoid double accounting for pure zerocopy skbs")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Mat Martineau <mathew.j.martineau@linux.intel.com>
Cc: Talal Ahmad <talalahmad@google.com>
Cc: Arjun Roy <arjunroy@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Acked-by: Paolo Abeni <pabeni@redhat.com>
Link: https://lore.kernel.org/r/20220201184640.756716-1-eric.dumazet@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/tcp_input.c')
| -rw-r--r-- | net/ipv4/tcp_input.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c index dc49a3d551eb9..bfe4112e000c0 100644 --- a/net/ipv4/tcp_input.c +++ b/net/ipv4/tcp_input.c @@ -1660,6 +1660,8 @@ static struct sk_buff *tcp_shift_skb_data(struct sock *sk, struct sk_buff *skb, (mss != tcp_skb_seglen(skb))) goto out; + if (!tcp_skb_can_collapse(prev, skb)) + goto out; len = skb->len; pcount = tcp_skb_pcount(skb); if (tcp_skb_shift(prev, skb, pcount, len)) |