================================================================== BUG: KCSAN: data-race in prandom_seed / prandom_u32 read to 0xffff888237d28848 of 8 bytes by task 1905 on cpu 0: prandom_seed+0xbb/0x270 lib/random32.c:439 addrconf_dad_begin net/ipv6/addrconf.c:3975 [inline] addrconf_dad_work+0x265/0xbb0 net/ipv6/addrconf.c:4100 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289 worker_thread+0x618/0xa70 kernel/workqueue.c:2436 kthread+0x1a9/0x1e0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 write to 0xffff888237d28848 of 8 bytes by task 1829 on cpu 1: siprand_u32 lib/random32.c:372 [inline] prandom_u32+0x10e/0x190 lib/random32.c:387 prandom_u32_max include/linux/prandom.h:96 [inline] ip_idents_reserve net/ipv4/route.c:474 [inline] __ip_select_ident+0x12d/0x190 net/ipv4/route.c:496 iptunnel_xmit+0x2f6/0x490 net/ipv4/ip_tunnel_core.c:80 udp_tunnel_xmit_skb+0x15d/0x170 net/ipv4/udp_tunnel_core.c:171 send4+0x439/0x500 drivers/net/wireguard/socket.c:85 wg_socket_send_skb_to_peer+0x92/0x120 drivers/net/wireguard/socket.c:175 wg_socket_send_buffer_to_peer+0xd2/0xf0 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline] wg_packet_handshake_send_worker+0x109/0x150 drivers/net/wireguard/send.c:51 process_one_work+0x3d3/0x720 kernel/workqueue.c:2289 worker_thread+0x618/0xa70 kernel/workqueue.c:2436 kthread+0x1a9/0x1e0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 value changed: 0xeb4de494f1325140 -> 0x78d517bb7769ef6a Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 1829 Comm: kworker/u4:3 Not tainted 5.18.0-rc7-syzkaller-00006-g210e04ff7681-dirty #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: wg-kex-wg1 wg_packet_handshake_send_worker ==================================================================