linux-kernel - [17/89] brcmsmac: fix tx queue flush infinite loop

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 01 Feb 2012 12:59:41 -0800
From:	Greg KH <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
Cc:	torvalds@...ux-foundation.org, akpm@...ux-foundation.org,
	alan@...rguk.ukuu.org.uk, Stanislaw Gruszka <sgruszka@...hat.com>,
	"John W. Linville" <linville@...driver.com>
Subject: [17/89] brcmsmac: fix tx queue flush infinite loop

3.2-stable review patch.  If anyone has any objections, please let me know.

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

From: Stanislaw Gruszka <sgruszka@...hat.com>

commit f96b08a7e6f69c0f0a576554df3df5b1b519c479 upstream.

This patch workaround live deadlock problem caused by infinite loop
in brcms_c_wait_for_tx_completion(). I do not consider the patch as
the proper fix, which should fix the real reason of tx queue flush
failure, but patch helps with system lockup.

Reference:
https://bugzilla.kernel.org/show_bug.cgi?id=42576

Reported-and-tested-by: Patrick <ragamuffin@...acomm.ch>
Signed-off-by: Stanislaw Gruszka <sgruszka@...hat.com>
Signed-off-by: John W. Linville <linville@...driver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/net/wireless/brcm80211/brcmsmac/main.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/net/wireless/brcm80211/brcmsmac/main.c
+++ b/drivers/net/wireless/brcm80211/brcmsmac/main.c
@@ -8217,13 +8217,21 @@ int brcms_c_get_curband(struct brcms_c_i
 
 void brcms_c_wait_for_tx_completion(struct brcms_c_info *wlc, bool drop)
 {
+	int timeout = 20;
+
 	/* flush packet queue when requested */
 	if (drop)
 		brcmu_pktq_flush(&wlc->pkt_queue->q, false, NULL, NULL);
 
 	/* wait for queue and DMA fifos to run dry */
-	while (!pktq_empty(&wlc->pkt_queue->q) || brcms_txpktpendtot(wlc) > 0)
+	while (!pktq_empty(&wlc->pkt_queue->q) || brcms_txpktpendtot(wlc) > 0) {
 		brcms_msleep(wlc->wl, 1);
+
+		if (--timeout == 0)
+			break;
+	}
+
+	WARN_ON_ONCE(timeout == 0);
 }
 
 void brcms_c_set_beacon_listen_interval(struct brcms_c_info *wlc, u8 interval)


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/