From: Sasha Levin <sashal@kernel•org>
To: linux-kernel@vger•kernel.org, stable@vger•kernel.org
Cc: Brian Haley <haleyb.dev@gmail•com>,
Jakub Kicinski <kuba@kernel•org>, Sasha Levin <sashal@kernel•org>,
davem@davemloft•net, edumazet@google•com, pabeni@redhat•com,
corbet@lwn•net, den@openvz•org, razor@blackwall•org,
ulf.hansson@linaro•org, Jason@zx2c4•com, wangyuweihx@gmail•com,
daniel@iogearbox•net, thomas.zeitlhofer+lkml@ze-it•at,
alexander@mihalicyn•com, ja@ssi•bg, netdev@vger•kernel.org,
linux-doc@vger•kernel.org
Subject: [PATCH AUTOSEL 6.2 31/53] neighbor: fix proxy_delay usage when it is zero
Date: Sun, 26 Feb 2023 09:44:23 -0500 [thread overview]
Message-ID: <20230226144446.824580-31-sashal@kernel.org> (raw)
In-Reply-To: <20230226144446.824580-1-sashal@kernel.org>
From: Brian Haley <haleyb.dev@gmail•com>
[ Upstream commit 62e395f82d04510b0f86e5e603e29412be88596f ]
When set to zero, the neighbor sysctl proxy_delay value
does not cause an immediate reply for ARP/ND requests
as expected, it instead causes a random delay between
[0, U32_MAX). Looking at this comment from
__get_random_u32_below() explains the reason:
/*
* This function is technically undefined for ceil == 0, and in fact
* for the non-underscored constant version in the header, we build bug
* on that. But for the non-constant case, it's convenient to have that
* evaluate to being a straight call to get_random_u32(), so that
* get_random_u32_inclusive() can work over its whole range without
* undefined behavior.
*/
Added helper function that does not call get_random_u32_below()
if proxy_delay is zero and just uses the current value of
jiffies instead, causing pneigh_enqueue() to respond
immediately.
Also added definition of proxy_delay to ip-sysctl.txt since
it was missing.
Signed-off-by: Brian Haley <haleyb.dev@gmail•com>
Link: https://lore.kernel.org/r/20230130171428.367111-1-haleyb.dev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel•org>
Signed-off-by: Sasha Levin <sashal@kernel•org>
---
Documentation/networking/ip-sysctl.rst | 8 ++++++++
net/core/neighbour.c | 14 ++++++++++++--
2 files changed, 20 insertions(+), 2 deletions(-)
diff --git a/Documentation/networking/ip-sysctl.rst b/Documentation/networking/ip-sysctl.rst
index 7fbd060d60470..f0bf509d2321b 100644
--- a/Documentation/networking/ip-sysctl.rst
+++ b/Documentation/networking/ip-sysctl.rst
@@ -1589,6 +1589,14 @@ proxy_arp_pvlan - BOOLEAN
Hewlett-Packard call it Source-Port filtering or port-isolation.
Ericsson call it MAC-Forced Forwarding (RFC Draft).
+proxy_delay - INTEGER
+ Delay proxy response.
+
+ Delay response to a neighbor solicitation when proxy_arp
+ or proxy_ndp is enabled. A random value between [0, proxy_delay)
+ will be chosen, setting to zero means reply with no delay.
+ Value in jiffies. Defaults to 80.
+
shared_media - BOOLEAN
Send(router) or accept(host) RFC1620 shared media redirects.
Overrides secure_redirects.
diff --git a/net/core/neighbour.c b/net/core/neighbour.c
index 4edd2176e2385..6798f6d2423b9 100644
--- a/net/core/neighbour.c
+++ b/net/core/neighbour.c
@@ -1674,11 +1674,21 @@ static void neigh_proxy_process(struct timer_list *t)
spin_unlock(&tbl->proxy_queue.lock);
}
+static unsigned long neigh_proxy_delay(struct neigh_parms *p)
+{
+ /* If proxy_delay is zero, do not call get_random_u32_below()
+ * as it is undefined behavior.
+ */
+ unsigned long proxy_delay = NEIGH_VAR(p, PROXY_DELAY);
+
+ return proxy_delay ?
+ jiffies + get_random_u32_below(proxy_delay) : jiffies;
+}
+
void pneigh_enqueue(struct neigh_table *tbl, struct neigh_parms *p,
struct sk_buff *skb)
{
- unsigned long sched_next = jiffies +
- get_random_u32_below(NEIGH_VAR(p, PROXY_DELAY));
+ unsigned long sched_next = neigh_proxy_delay(p);
if (p->qlen > NEIGH_VAR(p, PROXY_QLEN)) {
kfree_skb(skb);
--
2.39.0
next prev parent reply other threads:[~2023-02-26 14:48 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-26 14:43 [PATCH AUTOSEL 6.2 01/53] wifi: ath9k: Fix use-after-free in ath9k_hif_usb_disconnect() Sasha Levin
2023-02-26 14:43 ` [PATCH AUTOSEL 6.2 02/53] wifi: ath11k: fix monitor mode bringup crash Sasha Levin
2023-02-26 14:43 ` [PATCH AUTOSEL 6.2 03/53] wifi: brcmfmac: Fix potential stack-out-of-bounds in brcmf_c_preinit_dcmds() Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 09/53] wifi: ath11k: debugfs: fix to work with multiple PCI devices Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 14/53] wifi: brcmfmac: ensure CLM version is null-terminated to prevent stack-out-of-bounds Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 15/53] wifi: rtw89: fix assignation of TX BD RAM table Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 16/53] wifi: mt7601u: fix an integer underflow Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 17/53] inet: fix fast path in __inet_hash_connect() Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 18/53] ice: restrict PTP HW clock freq adjustments to 100, 000, 000 PPB Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 19/53] ice: add missing checks for PF vsi type Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 26/53] netpoll: Remove 4s sleep during carrier detection Sasha Levin
2023-02-27 18:15 ` Jakub Kicinski
2023-03-01 2:10 ` Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 27/53] net: bcmgenet: Add a check for oversized packets Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 30/53] netfilter: nf_tables: NULL pointer dereference in nf_tables_updobj() Sasha Levin
2023-02-26 14:44 ` Sasha Levin [this message]
2023-02-27 18:15 ` [PATCH AUTOSEL 6.2 31/53] neighbor: fix proxy_delay usage when it is zero Jakub Kicinski
2023-03-01 14:13 ` Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 32/53] can: isotp: check CAN address family in isotp_bind() Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 36/53] wifi: mt76: dma: free rx_head in mt76_dma_rx_cleanup Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 38/53] net/mlx5: fw_tracer: Fix debug print Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 48/53] wifi: rtw89: debug: avoid invalid access on RTW89_DBG_SEL_MAC_30 Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 49/53] hv_netvsc: Check status in SEND_RNDIS_PKT completion message Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 51/53] devlink: health: Fix nla_nest_end in error flow Sasha Levin
2023-02-27 18:13 ` Jakub Kicinski
2023-03-01 14:13 ` Sasha Levin
2023-02-26 14:44 ` [PATCH AUTOSEL 6.2 53/53] scm: add user copy checks to put_cmsg() Sasha Levin
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