| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Message-ID: <20250331075946.31960-1-edumazet@google.com>
Date: Mon, 31 Mar 2025 07:59:46 +0000
From: Eric Dumazet <edumazet@...gle.com>
To: "David S . Miller" <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>, Neal Cardwell <ncardwell@...gle.com>
Cc: Simon Horman <horms@...nel.org>, netdev@...r.kernel.org,
Willem de Bruijn <willemb@...gle.com>, Kuniyuki Iwashima <kuniyu@...zon.com>, eric.dumazet@...il.com,
Eric Dumazet <edumazet@...gle.com>
Subject: [PATCH net] Revert "tcp: avoid atomic operations on sk->sk_rmem_alloc"
This reverts commit 0de2a5c4b824da2205658ebebb99a55c43cdf60f.
I forgot that a TCP socket could receive messages in its error queue.
sock_queue_err_skb() can be called without socket lock being held,
and changes sk->sk_rmem_alloc.
The fact that skbs in error queue are limited by sk->sk_rcvbuf
means that error messages can be dropped if socket receive
queues are full, which is an orthogonal issue.
In future kernels, we could use a separate sk->sk_error_mem_alloc
counter specifically for the error queue.
Fixes: 0de2a5c4b824 ("tcp: avoid atomic operations on sk->sk_rmem_alloc")
Signed-off-by: Eric Dumazet <edumazet@...gle.com>
---
include/net/tcp.h | 15 ---------------
net/ipv4/tcp.c | 18 ++----------------
net/ipv4/tcp_fastopen.c | 2 +-
net/ipv4/tcp_input.c | 6 +++---
4 files changed, 6 insertions(+), 35 deletions(-)
diff --git a/include/net/tcp.h b/include/net/tcp.h
index df04dc09c519d850579e22a17f49eeec7d22c607..4450c384ef178e860bd76c23653e9ce9d7a7289b 100644
--- a/include/net/tcp.h
+++ b/include/net/tcp.h
@@ -779,7 +779,6 @@ static inline int tcp_bound_to_half_wnd(struct tcp_sock *tp, int pktsize)
/* tcp.c */
void tcp_get_info(struct sock *, struct tcp_info *);
-void tcp_sock_rfree(struct sk_buff *skb);
/* Read 'sendfile()'-style from a TCP socket */
int tcp_read_sock(struct sock *sk, read_descriptor_t *desc,
@@ -2899,18 +2898,4 @@ enum skb_drop_reason tcp_inbound_hash(struct sock *sk,
const void *saddr, const void *daddr,
int family, int dif, int sdif);
-/* version of skb_set_owner_r() avoiding one atomic_add() */
-static inline void tcp_skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
-{
- skb_orphan(skb);
- skb->sk = sk;
- skb->destructor = tcp_sock_rfree;
-
- sock_owned_by_me(sk);
- atomic_set(&sk->sk_rmem_alloc,
- atomic_read(&sk->sk_rmem_alloc) + skb->truesize);
-
- sk_forward_alloc_add(sk, -skb->truesize);
-}
-
#endif /* _TCP_H */
diff --git a/net/ipv4/tcp.c b/net/ipv4/tcp.c
index ea8de00f669d059d97766529e3b8c53d5040456d..6edc441b37023de48281aa810aa7a36199fd8bc3 100644
--- a/net/ipv4/tcp.c
+++ b/net/ipv4/tcp.c
@@ -1525,25 +1525,11 @@ void tcp_cleanup_rbuf(struct sock *sk, int copied)
__tcp_cleanup_rbuf(sk, copied);
}
-/* private version of sock_rfree() avoiding one atomic_sub() */
-void tcp_sock_rfree(struct sk_buff *skb)
-{
- struct sock *sk = skb->sk;
- unsigned int len = skb->truesize;
-
- sock_owned_by_me(sk);
- atomic_set(&sk->sk_rmem_alloc,
- atomic_read(&sk->sk_rmem_alloc) - len);
-
- sk_forward_alloc_add(sk, len);
- sk_mem_reclaim(sk);
-}
-
static void tcp_eat_recv_skb(struct sock *sk, struct sk_buff *skb)
{
__skb_unlink(skb, &sk->sk_receive_queue);
- if (likely(skb->destructor == tcp_sock_rfree)) {
- tcp_sock_rfree(skb);
+ if (likely(skb->destructor == sock_rfree)) {
+ sock_rfree(skb);
skb->destructor = NULL;
skb->sk = NULL;
return skb_attempt_defer_free(skb);
diff --git a/net/ipv4/tcp_fastopen.c b/net/ipv4/tcp_fastopen.c
index ca40665145c692ce0de518886bb366406606f7ac..1a6b1bc5424514e27a99cbb2fcedf001afd51d98 100644
--- a/net/ipv4/tcp_fastopen.c
+++ b/net/ipv4/tcp_fastopen.c
@@ -189,7 +189,7 @@ void tcp_fastopen_add_skb(struct sock *sk, struct sk_buff *skb)
tcp_segs_in(tp, skb);
__skb_pull(skb, tcp_hdrlen(skb));
sk_forced_mem_schedule(sk, skb->truesize);
- tcp_skb_set_owner_r(skb, sk);
+ skb_set_owner_r(skb, sk);
TCP_SKB_CB(skb)->seq++;
TCP_SKB_CB(skb)->tcp_flags &= ~TCPHDR_SYN;
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index e1f952fbac48dfdc4f4f75a50a85b4904b93bbe2..a35018e2d0ba27b14d0b59d3728f7181b1a51161 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -5171,7 +5171,7 @@ static void tcp_data_queue_ofo(struct sock *sk, struct sk_buff *skb)
if (tcp_is_sack(tp))
tcp_grow_window(sk, skb, false);
skb_condense(skb);
- tcp_skb_set_owner_r(skb, sk);
+ skb_set_owner_r(skb, sk);
}
}
@@ -5187,7 +5187,7 @@ static int __must_check tcp_queue_rcv(struct sock *sk, struct sk_buff *skb,
tcp_rcv_nxt_update(tcp_sk(sk), TCP_SKB_CB(skb)->end_seq);
if (!eaten) {
tcp_add_receive_queue(sk, skb);
- tcp_skb_set_owner_r(skb, sk);
+ skb_set_owner_r(skb, sk);
}
return eaten;
}
@@ -5504,7 +5504,7 @@ tcp_collapse(struct sock *sk, struct sk_buff_head *list, struct rb_root *root,
__skb_queue_before(list, skb, nskb);
else
__skb_queue_tail(&tmp, nskb); /* defer rbtree insertion */
- tcp_skb_set_owner_r(nskb, sk);
+ skb_set_owner_r(nskb, sk);
mptcp_skb_ext_move(nskb, skb);
/* Copy data, releasing collapsed skbs. */
--
2.49.0.472.ge94155a9ec-goog
Powered by blists - more mailing lists