Netdev Archive on lore.kernel.org
 help / color / Atom feed
From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Yibo Zhao <yiboz@codeaurora.org>,
	Zhi Chen <zhichen@codeaurora.org>,
	Johannes Berg <johannes.berg@intel.com>,
	Sasha Levin <sashal@kernel.org>,
	linux-wireless@vger.kernel.org, netdev@vger.kernel.org
Subject: [PATCH AUTOSEL 4.14 24/35] mac80211: only warn once on chanctx_conf being NULL
Date: Wed, 26 Jun 2019 20:39:12 -0400
Message-ID: <20190627003925.21330-24-sashal@kernel.org> (raw)
In-Reply-To: <20190627003925.21330-1-sashal@kernel.org>

From: Yibo Zhao <yiboz@codeaurora.org>

[ Upstream commit 563572340173865a9a356e6bb02579e6998a876d ]

In multiple SSID cases, it takes time to prepare every AP interface
to be ready in initializing phase. If a sta already knows everything it
needs to join one of the APs and sends authentication to the AP which
is not fully prepared at this point of time, AP's channel context
could be NULL. As a result, warning message occurs.

Even worse, if the AP is under attack via tools such as MDK3 and massive
authentication requests are received in a very short time, console will
be hung due to kernel warning messages.

WARN_ON_ONCE() could be a better way for indicating warning messages
without duplicate messages to flood the console.

Johannes: We still need to address the underlying problem, but we
          don't really have a good handle on it yet. Suppress the
          worst side-effects for now.

Signed-off-by: Zhi Chen <zhichen@codeaurora.org>
Signed-off-by: Yibo Zhao <yiboz@codeaurora.org>
[johannes: add note, change subject]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 net/mac80211/ieee80211_i.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 894937bcd479..9765a54d7dbe 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -1405,7 +1405,7 @@ ieee80211_get_sband(struct ieee80211_sub_if_data *sdata)
 	rcu_read_lock();
 	chanctx_conf = rcu_dereference(sdata->vif.chanctx_conf);
 
-	if (WARN_ON(!chanctx_conf)) {
+	if (WARN_ON_ONCE(!chanctx_conf)) {
 		rcu_read_unlock();
 		return NULL;
 	}
-- 
2.20.1


  parent reply index

Thread overview: 25+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20190627003925.21330-1-sashal@kernel.org>
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 02/35] samples, bpf: fix to change the buffer size for read() Sasha Levin
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 03/35] bpf: sockmap, fix use after free from sleep in psock backlog workqueue Sasha Levin
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 05/35] mac80211: mesh: fix RCU warning Sasha Levin
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 06/35] mac80211: free peer keys before vif down in mesh Sasha Levin
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 07/35] mwifiex: Fix possible buffer overflows at parsing bss descriptor Sasha Levin
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 08/35] mwifiex: Abort at too short BSS descriptor element Sasha Levin
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 09/35] iwlwifi: Fix double-free problems in iwl_req_fw_callback() Sasha Levin
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 10/35] bpf: udp: Avoid calling reuseport's bpf_prog from udp_gro Sasha Levin
2019-06-27  0:38 ` [PATCH AUTOSEL 4.14 11/35] netfilter: ipv6: nf_defrag: fix leakage of unqueued fragments Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 12/35] netfilter: ipv6: nf_defrag: accept duplicate fragments again Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 13/35] dt-bindings: can: mcp251x: add mcp25625 support Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 14/35] can: mcp251x: add support for mcp25625 Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 15/35] can: m_can: implement errata "Needless activation of MRAF irq" Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 16/35] can: af_can: Fix error path of can_init() Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 17/35] ibmvnic: Refresh device multicast list after reset Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 21/35] mlxsw: spectrum: Disallow prio-tagged packets when PVID is removed Sasha Levin
2019-06-27  0:39 ` Sasha Levin [this message]
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 25/35] qmi_wwan: add support for QMAP padding in the RX path Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 26/35] qmi_wwan: avoid RCU stalls on device disconnect when in QMAP mode Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 27/35] qmi_wwan: extend permitted QMAP mux_id value range Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 29/35] bnx2x: Check if transceiver implements DDM before access Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 31/35] ip6_tunnel: allow not to count pkts on tstats by passing dev as NULL Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 32/35] net: lio_core: fix potential sign-extension overflow on large shift Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 34/35] net: dsa: mv88e6xxx: fix shift of FID bits in mv88e6185_g1_vtu_loadpurge() Sasha Levin
2019-06-27  0:39 ` [PATCH AUTOSEL 4.14 35/35] net :sunrpc :clnt :Fix xps refcount imbalance on the error path Sasha Levin

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20190627003925.21330-24-sashal@kernel.org \
    --to=sashal@kernel.org \
    --cc=johannes.berg@intel.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-wireless@vger.kernel.org \
    --cc=netdev@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    --cc=yiboz@codeaurora.org \
    --cc=zhichen@codeaurora.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Netdev Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/netdev/0 netdev/git/0.git
	git clone --mirror https://lore.kernel.org/netdev/1 netdev/git/1.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 netdev netdev/ https://lore.kernel.org/netdev \
		netdev@vger.kernel.org netdev@archiver.kernel.org
	public-inbox-index netdev

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.netdev


AGPL code for this site: git clone https://public-inbox.org/ public-inbox