syzbot

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BUG: KASAN: null-ptr-deref in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: null-ptr-deref in atomic_add_negative_relaxed include/linux/atomic/atomic-instrumented.h:1475 [inline]
BUG: KASAN: null-ptr-deref in rcuref_get include/linux/rcuref.h:87 [inline]
BUG: KASAN: null-ptr-deref in dst_hold include/net/dst.h:241 [inline]
BUG: KASAN: null-ptr-deref in dst_cache_per_cpu_get+0x7d/0x290 net/core/dst_cache.c:51
Write of size 4 at addr 00000000000000d4 by task kworker/u8:12/3492

CPU: 0 UID: 0 PID: 3492 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: wg-kex-wg2 wg_packet_handshake_send_worker
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_add_negative_relaxed include/linux/atomic/atomic-instrumented.h:1475 [inline]
 rcuref_get include/linux/rcuref.h:87 [inline]
 dst_hold include/net/dst.h:241 [inline]
 dst_cache_per_cpu_get+0x7d/0x290 net/core/dst_cache.c:51
 dst_cache_get_ip4+0x235/0x800 net/core/dst_cache.c:91
 send4+0x354/0xed0 drivers/net/wireguard/socket.c:49
 wg_socket_send_skb_to_peer+0xd1/0x1d0 drivers/net/wireguard/socket.c:175
 wg_packet_send_handshake_initiation drivers/net/wireguard/send.c:40 [inline]
 wg_packet_handshake_send_worker+0x1db/0x320 drivers/net/wireguard/send.c:51
 process_one_work kernel/workqueue.c:3257 [inline]
 process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
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