From: Ahmed Zaki anzaki@gmail.com
stable inclusion from stable-v5.10.137 commit c35c01a7cb3002b86f7c245b9e5e3e76a331d738 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I60PLB
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 8f9dcc29566626f683843ccac6113a12208315ca upstream.
The following is from a system that went OOM due to a memory leak:
wlan0: Allocated STA 74:83:c2:64:0b:87 wlan0: Allocated STA 74:83:c2:64:0b:87 wlan0: IBSS finish 74:83:c2:64:0b:87 (---from ieee80211_ibss_add_sta) wlan0: Adding new IBSS station 74:83:c2:64:0b:87 wlan0: moving STA 74:83:c2:64:0b:87 to state 2 wlan0: moving STA 74:83:c2:64:0b:87 to state 3 wlan0: Inserted STA 74:83:c2:64:0b:87 wlan0: IBSS finish 74:83:c2:64:0b:87 (---from ieee80211_ibss_work) wlan0: Adding new IBSS station 74:83:c2:64:0b:87 wlan0: moving STA 74:83:c2:64:0b:87 to state 2 wlan0: moving STA 74:83:c2:64:0b:87 to state 3 . . wlan0: expiring inactive not authorized STA 74:83:c2:64:0b:87 wlan0: moving STA 74:83:c2:64:0b:87 to state 2 wlan0: moving STA 74:83:c2:64:0b:87 to state 1 wlan0: Removed STA 74:83:c2:64:0b:87 wlan0: Destroyed STA 74:83:c2:64:0b:87
The ieee80211_ibss_finish_sta() is called twice on the same STA from 2 different locations. On the second attempt, the allocated STA is not destroyed creating a kernel memory leak.
This is happening because sta_info_insert_finish() does not call sta_info_free() the second time when the STA already exists (returns -EEXIST). Note that the caller sta_info_insert_rcu() assumes STA is destroyed upon errors.
Same fix is applied to -ENOMEM.
Signed-off-by: Ahmed Zaki anzaki@gmail.com Link: https://lore.kernel.org/r/20211002145329.3125293-1-anzaki@gmail.com [change the error path label to use the existing code] Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Viacheslav Sablin sablin@ispras.ru Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Reviewed-by: Wei Li liwei391@huawei.com --- net/mac80211/sta_info.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/mac80211/sta_info.c b/net/mac80211/sta_info.c index e18c3855f616..461c03737da8 100644 --- a/net/mac80211/sta_info.c +++ b/net/mac80211/sta_info.c @@ -645,13 +645,13 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU) /* check if STA exists already */ if (sta_info_get_bss(sdata, sta->sta.addr)) { err = -EEXIST; - goto out_err; + goto out_cleanup; }
sinfo = kzalloc(sizeof(struct station_info), GFP_KERNEL); if (!sinfo) { err = -ENOMEM; - goto out_err; + goto out_cleanup; }
local->num_sta++; @@ -707,8 +707,8 @@ static int sta_info_insert_finish(struct sta_info *sta) __acquires(RCU) out_drop_sta: local->num_sta--; synchronize_net(); + out_cleanup: cleanup_single_sta(sta); - out_err: mutex_unlock(&local->sta_mtx); kfree(sinfo); rcu_read_lock();