[PATCH AUTOSEL 5.17 37/60] Revert "net: af_key: add check for pfkey_broadcast in function pfkey_process"

[PATCH AUTOSEL 5.17 37/60] Revert "net: af_key: add check for pfkey_broadcast in function pfkey_process"

[Sasha Levin]

From: Michal Kubecek <mkubecek@suse.cz>

[ Upstream commit 9c90c9b3e50e16d03c7f87d63e9db373974781e0 ]

This reverts commit 4dc2a5a8f6754492180741facf2a8787f2c415d7.

A non-zero return value from pfkey_broadcast() does not necessarily mean
an error occurred as this function returns -ESRCH when no registered
listener received the message. In particular, a call with
BROADCAST_PROMISC_ONLY flag and null one_sk argument can never return
zero so that this commit in fact prevents processing any PF_KEY message.
One visible effect is that racoon daemon fails to find encryption
algorithms like aes and refuses to start.

Excluding -ESRCH return value would fix this but it's not obvious that
we really want to bail out here and most other callers of
pfkey_broadcast() also ignore the return value. Also, as pointed out by
Steffen Klassert, PF_KEY is kind of deprecated and newer userspace code
should use netlink instead so that we should only disturb the code for
really important fixes.

v2: add a comment explaining why is the return value ignored

Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/key/af_key.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/net/key/af_key.c b/net/key/af_key.c
index 339d95df19d3..d93bde657359 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -2826,10 +2826,12 @@ static int pfkey_process(struct sock *sk, struct sk_buff *skb, const struct sadb
 	void *ext_hdrs[SADB_EXT_MAX];
 	int err;
 
-	err = pfkey_broadcast(skb_clone(skb, GFP_KERNEL), GFP_KERNEL,
-			      BROADCAST_PROMISC_ONLY, NULL, sock_net(sk));
-	if (err)
-		return err;
+	/* Non-zero return value of pfkey_broadcast() does not always signal
+	 * an error and even on an actual error we may still want to process
+	 * the message so rather ignore the return value.
+	 */
+	pfkey_broadcast(skb_clone(skb, GFP_KERNEL), GFP_KERNEL,
+			BROADCAST_PROMISC_ONLY, NULL, sock_net(sk));
 
 	memset(ext_hdrs, 0, sizeof(ext_hdrs));
 	err = parse_exthdrs(skb, hdr, ext_hdrs);
-- 
2.35.1

[PATCH AUTOSEL 5.17 40/60] net, neigh: Set lower cap for neigh_managed_work rearming

[Sasha Levin]

From: Daniel Borkmann <daniel@iogearbox.net>

[ Upstream commit ed6cd6a17896561b9f51ab4c0d9bbb29e762b597 ]

Yuwei reported that plain reuse of DELAY_PROBE_TIME to rearm work queue
in neigh_managed_work is problematic if user explicitly configures the
DELAY_PROBE_TIME to 0 for a neighbor table. Such misconfig can then hog
CPU to 100% processing the system work queue. Instead, set lower interval
bound to HZ which is totally sufficient. Yuwei is additionally looking
into making the interval separately configurable from DELAY_PROBE_TIME.

Reported-by: Yuwei Wang <wangyuweihx@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/netdev/797c3c53-ce1b-9f60-e253-cda615788f4a@iogearbox.net
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://lore.kernel.org/r/3b8c5aa906c52c3a8c995d1b2e8ccf650ea7c716.1653432794.git.daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/core/neighbour.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index ec0bf737b076..a252f4090d75 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1579,7 +1579,7 @@ static void neigh_managed_work(struct work_struct *work)
 	list_for_each_entry(neigh, &tbl->managed_list, managed_list)
 		neigh_event_send_probe(neigh, NULL, false);
 	queue_delayed_work(system_power_efficient_wq, &tbl->managed_work,
-			   NEIGH_VAR(&tbl->parms, DELAY_PROBE_TIME));
+			   max(NEIGH_VAR(&tbl->parms, DELAY_PROBE_TIME), HZ));
 	write_unlock_bh(&tbl->lock);
 }
 
-- 
2.35.1