netdev - [PATCH][MAC80211]: Do not free net device after it is unregistered.

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-next>] [day] [month] [year] [list]

Message-ID: <481D5D79.5080702@openvz.org>
Date:	Sun, 04 May 2008 10:53:45 +0400
From:	Pavel Emelyanov <xemul@...nvz.org>
To:	Johannes Berg <johannes@...solutions.net>,
	"John W. Linville" <linville@...driver.com>
CC:	linux-wireless@...r.kernel.org,
	Linux Netdev List <netdev@...r.kernel.org>
Subject: [PATCH][MAC80211]: Do not free net device after it is unregistered.

The error path in ieee80211_register_hw() may call the unregister_netdev()
and right after it - the free_netdev(), which is wrong, since the
unregister releases the device itself.

So the proposed fix is to NULL the local->mdev after unregister is done
and check this before calling free_netdev().

I checked - no code uses the local->mdev after unregister in this error
path (but even if some did this would be a BUG).

Signed-off-by: Pavel Emelyanov <xemul@...nvz.org>

---
 net/mac80211/main.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/net/mac80211/main.c b/net/mac80211/main.c
index 9ad4e36..915afad 100644
--- a/net/mac80211/main.c
+++ b/net/mac80211/main.c
@@ -1766,6 +1766,7 @@ fail_wep:
 fail_rate:
 	ieee80211_debugfs_remove_netdev(IEEE80211_DEV_TO_SUB_IF(local->mdev));
 	unregister_netdevice(local->mdev);
+	local->mdev = NULL;
 fail_dev:
 	rtnl_unlock();
 	sta_info_stop(local);
@@ -1773,8 +1774,10 @@ fail_sta_info:
 	debugfs_hw_del(local);
 	destroy_workqueue(local->hw.workqueue);
 fail_workqueue:
-	ieee80211_if_free(local->mdev);
-	local->mdev = NULL;
+	if (local->mdev != NULL) {
+		ieee80211_if_free(local->mdev);
+		local->mdev = NULL;
+	}
 fail_mdev_alloc:
 	wiphy_unregister(local->hw.wiphy);
 	return result;
-- 
1.5.3.4

--
To unsubscribe from this list: send the line "unsubscribe netdev" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html