================================================================== 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:67 [inline] BUG: KASAN: null-ptr-deref in dst_hold include/net/dst.h:238 [inline] BUG: KASAN: null-ptr-deref in dst_cache_per_cpu_get+0xb0/0x370 net/core/dst_cache.c:50 Write of size 4 at addr 0000000000000043 by task kworker/0:6/6573 CPU: 0 UID: 0 PID: 6573 Comm: kworker/0:6 Not tainted 6.15.0-rc7-syzkaller-gd7fa1af5b33e #0 PREEMPT Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker Call trace: show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack+0x30/0x40 lib/dump_stack.c:94 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120 print_report+0x58/0x84 mm/kasan/report.c:524 kasan_report+0xb0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:-1 [inline] kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:189 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37 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:67 [inline] dst_hold include/net/dst.h:238 [inline] dst_cache_per_cpu_get+0xb0/0x370 net/core/dst_cache.c:50 dst_cache_get_ip4+0xa0/0x154 net/core/dst_cache.c:84 send4+0x2a0/0xbc8 drivers/net/wireguard/socket.c:49 wg_socket_send_skb_to_peer+0xc4/0x1a4 drivers/net/wireguard/socket.c:175 wg_socket_send_buffer_to_peer+0x104/0x168 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_response+0x15c/0x24c drivers/net/wireguard/send.c:103 wg_receive_handshake_packet drivers/net/wireguard/receive.c:154 [inline] wg_packet_handshake_receive_worker+0x4fc/0xc20 drivers/net/wireguard/receive.c:213 process_one_work+0x7e8/0x156c kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3400 kthread+0x5fc/0x75c kernel/kthread.c:464 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847 ================================================================== Unable to handle kernel NULL pointer dereference at virtual address 0000000000000043 Mem abort info: ESR = 0x0000000096000021 EC = 0x25: DABT (current EL), IL = 32 bits SET = 0, FnV = 0 EA = 0, S1PTW = 0 FSC = 0x21: alignment fault Data abort info: ISV = 0, ISS = 0x00000021, ISS2 = 0x00000000 CM = 0, WnR = 0, TnD = 0, TagAccess = 0 GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 user pgtable: 4k pages, 48-bit VAs, pgdp=00000001174c7000 [0000000000000043] pgd=0800000115443403, p4d=0800000115443403, pud=0800000131392403, pmd=0000000000000000 Internal error: Oops: 0000000096000021 [#1] SMP Modules linked in: CPU: 0 UID: 0 PID: 6573 Comm: kworker/0:6 Tainted: G B 6.15.0-rc7-syzkaller-gd7fa1af5b33e #0 PREEMPT Tainted: [B]=BAD_PAGE Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 Workqueue: wg-kex-wg2 wg_packet_handshake_receive_worker pstate: 80400005 (Nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __lse_atomic_fetch_add_relaxed arch/arm64/include/asm/atomic_lse.h:62 [inline] pc : __lse_atomic_add_return_relaxed arch/arm64/include/asm/atomic_lse.h:94 [inline] pc : arch_atomic_add_return_relaxed arch/arm64/include/asm/atomic.h:52 [inline] pc : raw_atomic_add_return_relaxed include/linux/atomic/atomic-arch-fallback.h:644 [inline] pc : raw_atomic_add_negative_relaxed include/linux/atomic/atomic-arch-fallback.h:2403 [inline] pc : atomic_add_negative_relaxed include/linux/atomic/atomic-instrumented.h:1476 [inline] pc : rcuref_get include/linux/rcuref.h:67 [inline] pc : dst_hold include/net/dst.h:238 [inline] pc : dst_cache_per_cpu_get+0xbc/0x370 net/core/dst_cache.c:50 lr : __lse_atomic_fetch_add_relaxed arch/arm64/include/asm/atomic_lse.h:62 [inline] lr : __lse_atomic_add_return_relaxed arch/arm64/include/asm/atomic_lse.h:94 [inline] lr : arch_atomic_add_return_relaxed arch/arm64/include/asm/atomic.h:52 [inline] lr : raw_atomic_add_return_relaxed include/linux/atomic/atomic-arch-fallback.h:644 [inline] lr : raw_atomic_add_negative_relaxed include/linux/atomic/atomic-arch-fallback.h:2403 [inline] lr : atomic_add_negative_relaxed include/linux/atomic/atomic-instrumented.h:1476 [inline] lr : rcuref_get include/linux/rcuref.h:67 [inline] lr : dst_hold include/net/dst.h:238 [inline] lr : dst_cache_per_cpu_get+0xb8/0x370 net/core/dst_cache.c:50 sp : ffff8000a0ed7470 x29: ffff8000a0ed7480 x28: 1fffffbff7ef1f3f x27: 1fffe00019a033d1 x26: dfff800000000000 x25: ffff8000a0ed75c0 x24: 0000000000000043 x23: ffff0000cfc06460 x22: ffff0000cd019e88 x21: fffffdffbf78fa00 x20: 0000000000000003 x19: fffffdffbf78f9f8 x18: 00000000ffffffff x17: 0000000000000000 x16: ffff80008ad27e48 x15: 0000000000000001 x14: 1ffff00012553cfc x13: 0000000000000000 x12: 0000000000000000 x11: ffff700012553cfd x10: 0000000000ff0100 x9 : 0000000000000000 x8 : 0000000000000001 x7 : 0000000000000001 x6 : 0000000000000001 x5 : ffff8000a0ed6cd8 x4 : ffff80008f415ba0 x3 : ffff8000803b78c0 x2 : 0000000000000001 x1 : 0000000000000000 x0 : 0000000000000000 Call trace: __lse_atomic_fetch_add_relaxed arch/arm64/include/asm/atomic_lse.h:-1 [inline] (P) __lse_atomic_add_return_relaxed arch/arm64/include/asm/atomic_lse.h:94 [inline] (P) arch_atomic_add_return_relaxed arch/arm64/include/asm/atomic.h:52 [inline] (P) raw_atomic_add_return_relaxed include/linux/atomic/atomic-arch-fallback.h:644 [inline] (P) raw_atomic_add_negative_relaxed include/linux/atomic/atomic-arch-fallback.h:2403 [inline] (P) atomic_add_negative_relaxed include/linux/atomic/atomic-instrumented.h:1476 [inline] (P) rcuref_get include/linux/rcuref.h:67 [inline] (P) dst_hold include/net/dst.h:238 [inline] (P) dst_cache_per_cpu_get+0xbc/0x370 net/core/dst_cache.c:50 (P) dst_cache_get_ip4+0xa0/0x154 net/core/dst_cache.c:84 send4+0x2a0/0xbc8 drivers/net/wireguard/socket.c:49 wg_socket_send_skb_to_peer+0xc4/0x1a4 drivers/net/wireguard/socket.c:175 wg_socket_send_buffer_to_peer+0x104/0x168 drivers/net/wireguard/socket.c:200 wg_packet_send_handshake_response+0x15c/0x24c drivers/net/wireguard/send.c:103 wg_receive_handshake_packet drivers/net/wireguard/receive.c:154 [inline] wg_packet_handshake_receive_worker+0x4fc/0xc20 drivers/net/wireguard/receive.c:213 process_one_work+0x7e8/0x156c kernel/workqueue.c:3238 process_scheduled_works kernel/workqueue.c:3319 [inline] worker_thread+0x958/0xed8 kernel/workqueue.c:3400 kthread+0x5fc/0x75c kernel/kthread.c:464 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:847 Code: 97be635e d503201f 97be62c0 52800028 (b8280308) ---[ end trace 0000000000000000 ]--- ---------------- Code disassembly (best guess): 0: 97be635e bl 0xfffffffffef98d78 4: d503201f nop 8: 97be62c0 bl 0xfffffffffef98b08 c: 52800028 mov w8, #0x1 // #1 * 10: b8280308 ldadd w8, w8, [x24] <-- trapping instruction