package/kernel/mac80211/patches/subsys/360-mac80211-fix-a-memory-leak-where-sta_info-is-not-fre.patch

   1 From 4db561ae4a90c2d0e15996634567559e292dc9e5 Mon Sep 17 00:00:00 2001
   2 From: Ahmed Zaki <anzaki@gmail.com>
   3 Date: Sat, 2 Oct 2021 08:53:29 -0600
   4 Subject: [PATCH] mac80211: fix a memory leak where sta_info is not freed
   5
   6 commit 8f9dcc29566626f683843ccac6113a12208315ca upstream.
   7
   8 The following is from a system that went OOM due to a memory leak:
   9
  10 wlan0: Allocated STA 74:83:c2:64:0b:87
  11 wlan0: Allocated STA 74:83:c2:64:0b:87
  12 wlan0: IBSS finish 74:83:c2:64:0b:87 (---from ieee80211_ibss_add_sta)
  13 wlan0: Adding new IBSS station 74:83:c2:64:0b:87
  14 wlan0: moving STA 74:83:c2:64:0b:87 to state 2
  15 wlan0: moving STA 74:83:c2:64:0b:87 to state 3
  16 wlan0: Inserted STA 74:83:c2:64:0b:87
  17 wlan0: IBSS finish 74:83:c2:64:0b:87 (---from ieee80211_ibss_work)
  18 wlan0: Adding new IBSS station 74:83:c2:64:0b:87
  19 wlan0: moving STA 74:83:c2:64:0b:87 to state 2
  20 wlan0: moving STA 74:83:c2:64:0b:87 to state 3
  21 .
  22 .
  23 wlan0: expiring inactive not authorized STA 74:83:c2:64:0b:87
  24 wlan0: moving STA 74:83:c2:64:0b:87 to state 2
  25 wlan0: moving STA 74:83:c2:64:0b:87 to state 1
  26 wlan0: Removed STA 74:83:c2:64:0b:87
  27 wlan0: Destroyed STA 74:83:c2:64:0b:87
  28
  29 The ieee80211_ibss_finish_sta() is called twice on the same STA from 2
  30 different locations. On the second attempt, the allocated STA is not
  31 destroyed creating a kernel memory leak.
  32
  33 This is happening because sta_info_insert_finish() does not call
  34 sta_info_free() the second time when the STA already exists (returns
  35 -EEXIST). Note that the caller sta_info_insert_rcu() assumes STA is
  36 destroyed upon errors.
  37
  38 Same fix is applied to -ENOMEM.
  39
  40 Signed-off-by: Ahmed Zaki <anzaki@gmail.com>
  41 Link: https://lore.kernel.org/r/20211002145329.3125293-1-anzaki@gmail.com
  42 [change the error path label to use the existing code]
  43 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  44 Signed-off-by: Viacheslav Sablin <sablin@ispras.ru>
  45 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  46 ---
  47  net/mac80211/sta_info.c | 6 +++---
  48  1 file changed, 3 insertions(+), 3 deletions(-)
  49
  50 --- a/net/mac80211/sta_info.c
  51 +++ b/net/mac80211/sta_info.c
  52 @@ -646,13 +646,13 @@ static int sta_info_insert_finish(struct
  53         /* check if STA exists already */
  54         if (sta_info_get_bss(sdata, sta->sta.addr)) {
  55                 err = -EEXIST;
  56 -               goto out_err;
  57 +               goto out_cleanup;
  58         }
  59
  60         sinfo = kzalloc(sizeof(struct station_info), GFP_KERNEL);
  61         if (!sinfo) {
  62                 err = -ENOMEM;
  63 -               goto out_err;
  64 +               goto out_cleanup;
  65         }
  66
  67         local->num_sta++;
  68 @@ -708,8 +708,8 @@ static int sta_info_insert_finish(struct
  69   out_drop_sta:
  70         local->num_sta--;
  71         synchronize_net();
  72 + out_cleanup:
  73         cleanup_single_sta(sta);
  74 - out_err:
  75         mutex_unlock(&local->sta_mtx);
  76         kfree(sinfo);
  77         rcu_read_lock();