Re: [syzbot] memory leak in cfg80211_inform_single_bss_frame_data

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    87066fdd2e30 Revert "mm/secretmem: use refcount_t instead ..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16b55554b00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=d25eeb482b0f99b
dashboard link: https://syzkaller.appspot.com/bug?extid=7a942657a255a9d9b18a
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=171cf464b00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1396b19f300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7a942657a255a9d9b18a@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: memory leak
unreferenced object 0xffff88810f3c7980 (size 96):
  comm "kworker/u4:0", pid 8, jiffies 4294948721 (age 17.180s)
  hex dump (first 32 bytes):
    e5 90 aa e8 34 cf 05 00 00 00 00 00 00 00 00 00  ....4...........
    00 00 00 00 00 00 00 00 28 00 00 00 01 00 06 10  ........(.......
  backtrace:
    [<ffffffff83ee74a9>] cfg80211_inform_single_bss_frame_data+0x139/0x640 net/wireless/scan.c:2383
    [<ffffffff83ee79fb>] cfg80211_inform_bss_frame_data+0x4b/0x470 net/wireless/scan.c:2444
    [<ffffffff83f8865e>] ieee80211_bss_info_update+0x16e/0x460 net/mac80211/scan.c:190
    [<ffffffff83f9687a>] ieee80211_rx_bss_info net/mac80211/ibss.c:1119 [inline]
    [<ffffffff83f9687a>] ieee80211_rx_mgmt_probe_beacon+0x61a/0x970 net/mac80211/ibss.c:1608
    [<ffffffff83f972dc>] ieee80211_ibss_rx_queued_mgmt+0x23c/0x6e0 net/mac80211/ibss.c:1635
    [<ffffffff83f99347>] ieee80211_iface_process_skb net/mac80211/iface.c:1439 [inline]
    [<ffffffff83f99347>] ieee80211_iface_work+0x5f7/0x770 net/mac80211/iface.c:1493
    [<ffffffff81265dbf>] process_one_work+0x2cf/0x620 kernel/workqueue.c:2297
    [<ffffffff812666c9>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2444
    [<ffffffff8126fc48>] kthread+0x188/0x1d0 kernel/kthread.c:319
    [<ffffffff810022cf>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

BUG: memory leak
unreferenced object 0xffff88810f3c7b00 (size 96):
  comm "kworker/u4:0", pid 8, jiffies 4294948721 (age 17.180s)
  hex dump (first 32 bytes):
    f5 90 aa e8 34 cf 05 00 00 00 00 00 00 00 00 00  ....4...........
    00 00 00 00 00 00 00 00 28 00 00 00 01 00 06 10  ........(.......
  backtrace:
    [<ffffffff83ee74a9>] cfg80211_inform_single_bss_frame_data+0x139/0x640 net/wireless/scan.c:2383
    [<ffffffff83ee79fb>] cfg80211_inform_bss_frame_data+0x4b/0x470 net/wireless/scan.c:2444
    [<ffffffff83f8865e>] ieee80211_bss_info_update+0x16e/0x460 net/mac80211/scan.c:190
    [<ffffffff83f9687a>] ieee80211_rx_bss_info net/mac80211/ibss.c:1119 [inline]
    [<ffffffff83f9687a>] ieee80211_rx_mgmt_probe_beacon+0x61a/0x970 net/mac80211/ibss.c:1608
    [<ffffffff83f972dc>] ieee80211_ibss_rx_queued_mgmt+0x23c/0x6e0 net/mac80211/ibss.c:1635
    [<ffffffff83f99347>] ieee80211_iface_process_skb net/mac80211/iface.c:1439 [inline]
    [<ffffffff83f99347>] ieee80211_iface_work+0x5f7/0x770 net/mac80211/iface.c:1493
    [<ffffffff81265dbf>] process_one_work+0x2cf/0x620 kernel/workqueue.c:2297
    [<ffffffff812666c9>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2444
    [<ffffffff8126fc48>] kthread+0x188/0x1d0 kernel/kthread.c:319
    [<ffffffff810022cf>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

BUG: memory leak
unreferenced object 0xffff88810f3c7680 (size 96):
  comm "kworker/u4:1", pid 146, jiffies 4294948731 (age 17.080s)
  hex dump (first 32 bytes):
    e9 20 ac e8 34 cf 05 00 00 00 00 00 00 00 00 00  . ..4...........
    00 00 00 00 00 00 00 00 28 00 00 00 01 00 06 10  ........(.......
  backtrace:
    [<ffffffff83ee74a9>] cfg80211_inform_single_bss_frame_data+0x139/0x640 net/wireless/scan.c:2383
    [<ffffffff83ee79fb>] cfg80211_inform_bss_frame_data+0x4b/0x470 net/wireless/scan.c:2444
    [<ffffffff83f8865e>] ieee80211_bss_info_update+0x16e/0x460 net/mac80211/scan.c:190
    [<ffffffff83f9687a>] ieee80211_rx_bss_info net/mac80211/ibss.c:1119 [inline]
    [<ffffffff83f9687a>] ieee80211_rx_mgmt_probe_beacon+0x61a/0x970 net/mac80211/ibss.c:1608
    [<ffffffff83f972dc>] ieee80211_ibss_rx_queued_mgmt+0x23c/0x6e0 net/mac80211/ibss.c:1635
    [<ffffffff83f99347>] ieee80211_iface_process_skb net/mac80211/iface.c:1439 [inline]
    [<ffffffff83f99347>] ieee80211_iface_work+0x5f7/0x770 net/mac80211/iface.c:1493
    [<ffffffff81265dbf>] process_one_work+0x2cf/0x620 kernel/workqueue.c:2297
    [<ffffffff812666c9>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2444
    [<ffffffff8126fc48>] kthread+0x188/0x1d0 kernel/kthread.c:319
    [<ffffffff810022cf>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295

BUG: memory leak
unreferenced object 0xffff888111520f80 (size 96):
  comm "kworker/u4:1", pid 146, jiffies 4294948731 (age 17.080s)
  hex dump (first 32 bytes):
    fb 20 ac e8 34 cf 05 00 00 00 00 00 00 00 00 00  . ..4...........
    00 00 00 00 00 00 00 00 28 00 00 00 01 00 06 10  ........(.......
  backtrace:
    [<ffffffff83ee74a9>] cfg80211_inform_single_bss_frame_data+0x139/0x640 net/wireless/scan.c:2383
    [<ffffffff83ee79fb>] cfg80211_inform_bss_frame_data+0x4b/0x470 net/wireless/scan.c:2444
    [<ffffffff83f8865e>] ieee80211_bss_info_update+0x16e/0x460 net/mac80211/scan.c:190
    [<ffffffff83f9687a>] ieee80211_rx_bss_info net/mac80211/ibss.c:1119 [inline]
    [<ffffffff83f9687a>] ieee80211_rx_mgmt_probe_beacon+0x61a/0x970 net/mac80211/ibss.c:1608
    [<ffffffff83f972dc>] ieee80211_ibss_rx_queued_mgmt+0x23c/0x6e0 net/mac80211/ibss.c:1635
    [<ffffffff83f99347>] ieee80211_iface_process_skb net/mac80211/iface.c:1439 [inline]
    [<ffffffff83f99347>] ieee80211_iface_work+0x5f7/0x770 net/mac80211/iface.c:1493
    [<ffffffff81265dbf>] process_one_work+0x2cf/0x620 kernel/workqueue.c:2297
    [<ffffffff812666c9>] worker_thread+0x59/0x5d0 kernel/workqueue.c:2444
    [<ffffffff8126fc48>] kthread+0x188/0x1d0 kernel/kthread.c:319
    [<ffffffff810022cf>] ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295