=====================================================
BUG: KMSAN: uninit-value in check_pointer lib/vsprintf.c:705 [inline]
BUG: KMSAN: uninit-value in string+0x3cf/0x6f0 lib/vsprintf.c:717
 check_pointer lib/vsprintf.c:705 [inline]
 string+0x3cf/0x6f0 lib/vsprintf.c:717
 vsnprintf+0x2222/0x3650 lib/vsprintf.c:2795
 sprintf+0x214/0x260 lib/vsprintf.c:2997
 batadv_mcast_flags_log net/batman-adv/multicast.c:811 [inline]
 batadv_mcast_mla_flags_update net/batman-adv/multicast.c:846 [inline]
 __batadv_mcast_mla_update net/batman-adv/multicast.c:889 [inline]
 batadv_mcast_mla_update+0x4f5b/0x5790 net/batman-adv/multicast.c:915
 process_one_work+0xdb6/0x1820 kernel/workqueue.c:2307
 worker_thread+0x10b3/0x21e0 kernel/workqueue.c:2454
 kthread+0x3c7/0x500 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30

Local variable vfork created at:
 kernel_clone+0x77/0x1130 kernel/fork.c:2529
 kernel_thread+0x17a/0x240 kernel/fork.c:2619

CPU: 1 PID: 959 Comm: kworker/u4:4 Not tainted 5.17.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: bat_events batadv_mcast_mla_update
=====================================================