package/kernel/mac80211/patches/subsys/375-mac80211-fix-double-free-in-ibss_leave.patch

   1 From 7da363fba2fc8526dbf3f966bac6f03fec98f095 Mon Sep 17 00:00:00 2001
   2 From: Markus Theil <markus.theil@tu-ilmenau.de>
   3 Date: Sat, 13 Feb 2021 14:36:53 +0100
   4 Subject: [PATCH] mac80211: fix double free in ibss_leave
   5
   6 commit 3bd801b14e0c5d29eeddc7336558beb3344efaa3 upstream.
   7
   8 Clear beacon ie pointer and ie length after free
   9 in order to prevent double free.
  10
  11 ==================================================================
  12 BUG: KASAN: double-free or invalid-free \
  13 in ieee80211_ibss_leave+0x83/0xe0 net/mac80211/ibss.c:1876
  14
  15 CPU: 0 PID: 8472 Comm: syz-executor100 Not tainted 5.11.0-rc6-syzkaller #0
  16 Call Trace:
  17  __dump_stack lib/dump_stack.c:79 [inline]
  18  dump_stack+0x107/0x163 lib/dump_stack.c:120
  19  print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:230
  20  kasan_report_invalid_free+0x51/0x80 mm/kasan/report.c:355
  21  ____kasan_slab_free+0xcc/0xe0 mm/kasan/common.c:341
  22  kasan_slab_free include/linux/kasan.h:192 [inline]
  23  __cache_free mm/slab.c:3424 [inline]
  24  kfree+0xed/0x270 mm/slab.c:3760
  25  ieee80211_ibss_leave+0x83/0xe0 net/mac80211/ibss.c:1876
  26  rdev_leave_ibss net/wireless/rdev-ops.h:545 [inline]
  27  __cfg80211_leave_ibss+0x19a/0x4c0 net/wireless/ibss.c:212
  28  __cfg80211_leave+0x327/0x430 net/wireless/core.c:1172
  29  cfg80211_leave net/wireless/core.c:1221 [inline]
  30  cfg80211_netdev_notifier_call+0x9e8/0x12c0 net/wireless/core.c:1335
  31  notifier_call_chain+0xb5/0x200 kernel/notifier.c:83
  32  call_netdevice_notifiers_info+0xb5/0x130 net/core/dev.c:2040
  33  call_netdevice_notifiers_extack net/core/dev.c:2052 [inline]
  34  call_netdevice_notifiers net/core/dev.c:2066 [inline]
  35  __dev_close_many+0xee/0x2e0 net/core/dev.c:1586
  36  __dev_close net/core/dev.c:1624 [inline]
  37  __dev_change_flags+0x2cb/0x730 net/core/dev.c:8476
  38  dev_change_flags+0x8a/0x160 net/core/dev.c:8549
  39  dev_ifsioc+0x210/0xa70 net/core/dev_ioctl.c:265
  40  dev_ioctl+0x1b1/0xc40 net/core/dev_ioctl.c:511
  41  sock_do_ioctl+0x148/0x2d0 net/socket.c:1060
  42  sock_ioctl+0x477/0x6a0 net/socket.c:1177
  43  vfs_ioctl fs/ioctl.c:48 [inline]
  44  __do_sys_ioctl fs/ioctl.c:753 [inline]
  45  __se_sys_ioctl fs/ioctl.c:739 [inline]
  46  __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:739
  47  do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46
  48  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  49
  50 Reported-by: syzbot+93976391bf299d425f44@syzkaller.appspotmail.com
  51 Signed-off-by: Markus Theil <markus.theil@tu-ilmenau.de>
  52 Link: https://lore.kernel.org/r/20210213133653.367130-1-markus.theil@tu-ilmenau.de
  53 Signed-off-by: Johannes Berg <johannes.berg@intel.com>
  54 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  55 ---
  56  net/mac80211/ibss.c | 2 ++
  57  1 file changed, 2 insertions(+)
  58
  59 --- a/net/mac80211/ibss.c
  60 +++ b/net/mac80211/ibss.c
  61 @@ -1869,6 +1869,8 @@ int ieee80211_ibss_leave(struct ieee8021
  62
  63         /* remove beacon */
  64         kfree(sdata->u.ibss.ie);
  65 +       sdata->u.ibss.ie = NULL;
  66 +       sdata->u.ibss.ie_len = 0;
  67
  68         /* on the next join, re-program HT parameters */
  69         memset(&ifibss->ht_capa, 0, sizeof(ifibss->ht_capa));