linux-kernel - [22/36] cfg80211: dont get expired BSSes

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]

Message-Id: <20100806192116.385584228@clark.site>
Date:	Fri, 06 Aug 2010 12:20:03 -0700
From:	Greg KH <gregkh@...e.de>
To:	linux-kernel@...r.kernel.org, stable@...nel.org
Cc:	stable-review@...nel.org, torvalds@...ux-foundation.org,
	akpm@...ux-foundation.org, alan@...rguk.ukuu.org.uk,
	Johannes Berg <johannes.berg@...el.com>,
	"John W. Linville" <linville@...driver.com>
Subject: [22/36] cfg80211: dont get expired BSSes

2.6.34-stable review patch.  If anyone has any objections, please let us know.

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

From: Johannes Berg <johannes.berg@...el.com>

commit ccb6c1360f8dd43303c659db718e7e0b24175db5 upstream.

When kernel-internal users use cfg80211_get_bss()
to get a reference to a BSS struct, they may end
up getting one that would have been removed from
the list if there had been any userspace access
to the list. This leads to inconsistencies and
problems.

Fix it by making cfg80211_get_bss() ignore BSSes
that cfg80211_bss_expire() would remove.

Fixes http://bugzilla.intellinuxwireless.org/show_bug.cgi?id=2180

Reported-by: Jiajia Zheng <jiajia.zheng@...el.com>
Tested-by: Jiajia Zheng <jiajia.zheng@...el.com>
Signed-off-by: Johannes Berg <johannes.berg@...el.com>
Signed-off-by: John W. Linville <linville@...driver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@...e.de>

---
 net/wireless/scan.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -275,6 +275,7 @@ struct cfg80211_bss *cfg80211_get_bss(st
 {
 	struct cfg80211_registered_device *dev = wiphy_to_dev(wiphy);
 	struct cfg80211_internal_bss *bss, *res = NULL;
+	unsigned long now = jiffies;
 
 	spin_lock_bh(&dev->bss_lock);
 
@@ -283,6 +284,10 @@ struct cfg80211_bss *cfg80211_get_bss(st
 			continue;
 		if (channel && bss->pub.channel != channel)
 			continue;
+		/* Don't get expired BSS structs */
+		if (time_after(now, bss->ts + IEEE80211_SCAN_RESULT_EXPIRE) &&
+		    !atomic_read(&bss->hold))
+			continue;
 		if (is_bss(&bss->pub, bssid, ssid, ssid_len)) {
 			res = bss;
 			kref_get(&res->ref);


--
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/