From be28c14ac8bbe1ff0b2a18a06cd10981f90fc741 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 14 Jun 2023 12:47:04 -0700 Subject: [PATCH 1/2] udplite: Print deprecation notice. Recently syzkaller reported a 7-year-old null-ptr-deref [0] that occurs when a UDP-Lite socket tries to allocate a buffer under memory pressure. Someone should have stumbled on the bug much earlier if UDP-Lite had been used in a real app. Also, we do not always need a large UDP-Lite workload to hit the bug since UDP and UDP-Lite share the same memory accounting limit. Removing UDP-Lite would simplify UDP code removing a bunch of conditionals in fast path. Let's add a deprecation notice when UDP-Lite socket is created and schedule its removal to 2025. Link: https://lore.kernel.org/netdev/20230523163305.66466-1-kuniyu@amazon.com/ [0] Signed-off-by: Kuniyuki Iwashima Signed-off-by: Jakub Kicinski --- net/ipv4/udplite.c | 2 ++ net/ipv6/udplite.c | 4 ++++ 2 files changed, 6 insertions(+) diff --git a/net/ipv4/udplite.c b/net/ipv4/udplite.c index 56d94d23b9e0..143f93a12f25 100644 --- a/net/ipv4/udplite.c +++ b/net/ipv4/udplite.c @@ -22,6 +22,8 @@ static int udplite_sk_init(struct sock *sk) { udp_init_sock(sk); udp_sk(sk)->pcflag = UDPLITE_BIT; + pr_warn_once("UDP-Lite is deprecated and scheduled to be removed in 2025, " + "please contact the netdev mailing list\n"); return 0; } diff --git a/net/ipv6/udplite.c b/net/ipv6/udplite.c index 3bab0cc13697..8e010d07917a 100644 --- a/net/ipv6/udplite.c +++ b/net/ipv6/udplite.c @@ -8,6 +8,8 @@ * Changes: * Fixes: */ +#define pr_fmt(fmt) "UDPLite6: " fmt + #include #include #include "udp_impl.h" @@ -16,6 +18,8 @@ static int udplitev6_sk_init(struct sock *sk) { udpv6_init_sock(sk); udp_sk(sk)->pcflag = UDPLITE_BIT; + pr_warn_once("UDP-Lite is deprecated and scheduled to be removed in 2025, " + "please contact the netdev mailing list\n"); return 0; } From b144fcaf46d43b1471ad6e4de66235b8cebb3c87 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 14 Jun 2023 12:47:05 -0700 Subject: [PATCH 2/2] dccp: Print deprecation notice. DCCP was marked as Orphan in the MAINTAINERS entry 2 years ago in commit 054c4610bd05 ("MAINTAINERS: dccp: move Gerrit Renker to CREDITS"). It says we haven't heard from the maintainer for five years, so DCCP is not well maintained for 7 years now. Recently DCCP only receives updates for bugs, and major distros disable it by default. Removing DCCP would allow for better organisation of TCP fields to reduce the number of cache lines hit in the fast path. Let's add a deprecation notice when DCCP socket is created and schedule its removal to 2025. Signed-off-by: Kuniyuki Iwashima Signed-off-by: Jakub Kicinski --- net/dccp/proto.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/dccp/proto.c b/net/dccp/proto.c index a06b5641287a..b0ebf853cb07 100644 --- a/net/dccp/proto.c +++ b/net/dccp/proto.c @@ -191,6 +191,9 @@ int dccp_init_sock(struct sock *sk, const __u8 ctl_sock_initialized) struct dccp_sock *dp = dccp_sk(sk); struct inet_connection_sock *icsk = inet_csk(sk); + pr_warn_once("DCCP is deprecated and scheduled to be removed in 2025, " + "please contact the netdev mailing list\n"); + icsk->icsk_rto = DCCP_TIMEOUT_INIT; icsk->icsk_syn_retries = sysctl_dccp_request_retries; sk->sk_state = DCCP_CLOSED;