From: Shuah Khan <skhan@linuxfoundation.org>
To: kvalo@codeaurora.org, davem@davemloft.net, kuba@kernel.org
Cc: Shuah Khan <skhan@linuxfoundation.org>,
ath9k-devel@qca.qualcomm.com, linux-wireless@vger.kernel.org,
netdev@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 1/2] ath9k: hold RCU lock when calling ieee80211_find_sta_by_ifaddr()
Date: Thu, 11 Feb 2021 19:13:05 -0700 [thread overview]
Message-ID: <1cfa036227cfa9fdd04316c01e1d754f13a70d9e.1613090339.git.skhan@linuxfoundation.org> (raw)
In-Reply-To: <cover.1613090339.git.skhan@linuxfoundation.org>
ieee80211_find_sta_by_ifaddr() must be called under the RCU lock and
the resulting pointer is only valid under RCU lock as well.
Fix ath_tx_process_buffer() to hold RCU read lock before it calls
ieee80211_find_sta_by_ifaddr() and release it when the resulting
pointer is no longer needed.
This problem was found while reviewing code to debug RCU warn from
ath10k_wmi_tlv_parse_peer_stats_info() and a subsequent manual audit
of other callers of ieee80211_find_sta_by_ifaddr() that don't hold
RCU read lock.
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
---
- Note: This patch is compile tested. I don't have access to
hardware.
drivers/net/wireless/ath/ath9k/xmit.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/drivers/net/wireless/ath/ath9k/xmit.c b/drivers/net/wireless/ath/ath9k/xmit.c
index e60d4737fc6e..1d36aae3f7b6 100644
--- a/drivers/net/wireless/ath/ath9k/xmit.c
+++ b/drivers/net/wireless/ath/ath9k/xmit.c
@@ -701,6 +701,9 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
ts->ts_rateindex);
hdr = (struct ieee80211_hdr *) bf->bf_mpdu->data;
+
+ rcu_read_lock();
+
sta = ieee80211_find_sta_by_ifaddr(hw, hdr->addr1, hdr->addr2);
if (sta) {
struct ath_node *an = (struct ath_node *)sta->drv_priv;
@@ -725,6 +728,8 @@ static void ath_tx_process_buffer(struct ath_softc *sc, struct ath_txq *txq,
if (!flush)
ath_txq_schedule(sc, txq);
+
+ rcu_read_unlock();
}
static bool ath_lookup_legacy(struct ath_buf *bf)
--
2.27.0
next parent reply other threads:[~2021-02-12 2:14 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <cover.1613090339.git.skhan@linuxfoundation.org>
2021-02-12 2:13 ` Shuah Khan [this message]
2021-02-12 2:13 ` [PATCH] mt76: hold RCU lock when calling ieee80211_find_sta_by_ifaddr() Shuah Khan
2021-02-12 5:36 ` Felix Fietkau
2021-02-12 17:20 ` Shuah Khan
2021-02-12 2:13 ` [PATCH] rtw88: " Shuah Khan
2021-02-12 6:34 ` Felix Fietkau
2021-02-12 6:31 ` [PATCH 1/2] ath9k: " Felix Fietkau
2021-02-12 2:13 ` [PATCH 2/2] ath9k: fix ath_tx_process_buffer() potential null ptr dereference Shuah Khan
2021-02-16 7:03 ` Kalle Valo
2021-02-16 7:53 ` Felix Fietkau
2021-02-16 15:22 ` Shuah Khan
2021-02-17 7:30 ` Kalle Valo
2021-02-17 14:56 ` Shuah Khan
2021-02-17 20:28 ` Shuah Khan
2021-02-17 21:36 ` Felix Fietkau
Reply instructions:
You may reply publicly 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=1cfa036227cfa9fdd04316c01e1d754f13a70d9e.1613090339.git.skhan@linuxfoundation.org \
--to=skhan@linuxfoundation.org \
--cc=ath9k-devel@qca.qualcomm.com \
--cc=davem@davemloft.net \
--cc=kuba@kernel.org \
--cc=kvalo@codeaurora.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-wireless@vger.kernel.org \
--cc=netdev@vger.kernel.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
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).