diff options
| author | Vladislav Efanov <VEfanov@ispras.ru> | 2023-05-26 19:16:32 +0300 |
|---|---|---|
| committer | Simon Wunderlich <sw@simonwunderlich.de> | 2023-05-26 23:14:49 +0200 |
| commit | abac3ac97fe8734b620e7322a116450d7f90aa43 (patch) | |
| tree | 286962a4c0dd2977a5f1594df9cb30de180e6026 /net/batman-adv/distributed-arp-table.c | |
| parent | 44c026a73be8038f03dbdeef028b642880cf1511 (diff) | |
batman-adv: Broken sync while rescheduling delayed work
Syzkaller got a lot of crashes like:
KASAN: use-after-free Write in *_timers*
All of these crashes point to the same memory area:
The buggy address belongs to the object at ffff88801f870000
which belongs to the cache kmalloc-8k of size 8192
The buggy address is located 5320 bytes inside of
8192-byte region [ffff88801f870000, ffff88801f872000)
This area belongs to :
batadv_priv->batadv_priv_dat->delayed_work->timer_list
The reason for these issues is the lack of synchronization. Delayed
work (batadv_dat_purge) schedules new timer/work while the device
is being deleted. As the result new timer/delayed work is set after
cancel_delayed_work_sync() was called. So after the device is freed
the timer list contains pointer to already freed memory.
Found by Linux Verification Center (linuxtesting.org) with syzkaller.
Cc: stable@kernel.org
Fixes: 2f1dfbe18507 ("batman-adv: Distributed ARP Table - implement local storage")
Signed-off-by: Vladislav Efanov <VEfanov@ispras.ru>
Acked-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Diffstat (limited to 'net/batman-adv/distributed-arp-table.c')
| -rw-r--r-- | net/batman-adv/distributed-arp-table.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/batman-adv/distributed-arp-table.c b/net/batman-adv/distributed-arp-table.c index 6968e55eb971..28a939d56090 100644 --- a/net/batman-adv/distributed-arp-table.c +++ b/net/batman-adv/distributed-arp-table.c @@ -101,7 +101,6 @@ static void batadv_dat_purge(struct work_struct *work); */ static void batadv_dat_start_timer(struct batadv_priv *bat_priv) { - INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); queue_delayed_work(batadv_event_workqueue, &bat_priv->dat.work, msecs_to_jiffies(10000)); } @@ -819,6 +818,7 @@ int batadv_dat_init(struct batadv_priv *bat_priv) if (!bat_priv->dat.hash) return -ENOMEM; + INIT_DELAYED_WORK(&bat_priv->dat.work, batadv_dat_purge); batadv_dat_start_timer(bat_priv); batadv_tvlv_handler_register(bat_priv, batadv_dat_tvlv_ogm_handler_v1, |