From be28c14ac8bbe1ff0b2a18a06cd10981f90fc741 Mon Sep 17 00:00:00 2001 From: Kuniyuki Iwashima Date: Wed, 14 Jun 2023 12:47:04 -0700 Subject: [PATCH] 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; } -- 2.20.1