diff mbox

hostap: Do not free priv until timer handler hasn't actually stopped using it

Message ID 1392380269.5384.36.camel@tkhai (mailing list archive)
State Not Applicable, archived
Headers show

Commit Message

Kirill Tkhai Feb. 14, 2014, 12:17 p.m. UTC
Function del_timer() does not guarantee that timer was really deleted.
If the timer handler is beeing executed at the moment, the function
does nothing. So, it's possible to use already freed memory in the handler:

[ref: Documentation/DocBook/kernel-locking.tmpl]

This was found using grep and compile-tested only. Please, consider
applying or something similar to it.

Signed-off-by: Kirill Tkhai <ktkhai@parallels.com>
CC: Jouni Malinen <j@w1.fi>
CC: John W. Linville <linville@tuxdriver.com>
---
 drivers/net/wireless/hostap/hostap_ap.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)




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diff mbox

Patch

diff --git a/drivers/net/wireless/hostap/hostap_ap.c b/drivers/net/wireless/hostap/hostap_ap.c
index d36e252..5965255 100644
--- a/drivers/net/wireless/hostap/hostap_ap.c
+++ b/drivers/net/wireless/hostap/hostap_ap.c
@@ -147,7 +147,7 @@  static void ap_free_sta(struct ap_data *ap, struct sta_info *sta)
 
 	if (!sta->ap && sta->u.sta.challenge)
 		kfree(sta->u.sta.challenge);
-	del_timer(&sta->timer);
+	del_timer_sync(&sta->timer);
 #endif /* PRISM2_NO_KERNEL_IEEE80211_MGMT */
 
 	kfree(sta);