Commit be28c14a authored Jun 14, 2023 by Kuniyuki Iwashima Committed by Jakub Kicinski Jun 15, 2023

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 <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

parent 9a36e2d4

net/ipv4/udplite.c

+2 −0

Original line number	Diff line number	Diff line
		@@ -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;
		}

net/ipv6/udplite.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -8,6 +8,8 @@
		* Changes:
		* Fixes:
		*/
		#define pr_fmt(fmt) "UDPLite6: " fmt

		#include <linux/export.h>
		#include <linux/proc_fs.h>
		#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;
		}