Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18;
Content-Type: text/plain; charset="UTF-8"
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
MIME-Version: 1.0
From:   Ben Hutchings <ben@decadent.org.uk>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
CC:     akpm@linux-foundation.org, Denis Kirjanov <kda@linux-powerpc.org>,
        "Nicolai Stange" <nstange@suse.de>,
        "Kalle Valo" <kvalo@codeaurora.org>
Date:   Fri, 24 Apr 2020 00:03:50 +0100
Message-ID: <lsq.1587683028.183373099@decadent.org.uk>
Subject: [PATCH 3.16 003/245] libertas: don't exit from lbs_ibss_join_existing()
 with RCU read lock held
In-Reply-To: <lsq.1587683027.831233700@decadent.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

3.16.83-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Nicolai Stange <nstange@suse.de>

commit c7bf1fb7ddca331780b9a733ae308737b39f1ad4 upstream.

Commit e5e884b42639 ("libertas: Fix two buffer overflows at parsing bss
descriptor") introduced a bounds check on the number of supplied rates to
lbs_ibss_join_existing().

Unfortunately, it introduced a return path from within a RCU read side
critical section without a corresponding rcu_read_unlock(). Fix this.

Fixes: e5e884b42639 ("libertas: Fix two buffer overflows at parsing bss descriptor")
Signed-off-by: Nicolai Stange <nstange@suse.de>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
[bwh: Backported to 3.16: adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 drivers/net/wireless/libertas/cfg.c | 1 +
 1 file changed, 1 insertion(+)

--- a/drivers/net/wireless/libertas/cfg.c
+++ b/drivers/net/wireless/libertas/cfg.c
@@ -1855,6 +1855,7 @@ static int lbs_ibss_join_existing(struct
 		rates_max = rates_eid[1];
 		if (rates_max > MAX_RATES) {
 			lbs_deb_join("invalid rates");
+			rcu_read_unlock();
 			goto out;
 		}
 		rates = cmd.bss.rates;