watchdog: BUG: soft lockup - CPU#0 stuck for 21s! [syz.9.920:9857] Modules linked in: irq event stamp: 58380 hardirqs last enabled at (58379): [] irqentry_exit_to_kernel_mode_after_preempt include/linux/irq-entry-common.h:507 [inline] hardirqs last enabled at (58379): [] arm64_exit_to_kernel_mode+0x80/0x94 arch/arm64/kernel/entry-common.c:62 hardirqs last disabled at (58380): [] __el1_irq arch/arm64/kernel/entry-common.c:506 [inline] hardirqs last disabled at (58380): [] el1_interrupt+0x28/0x60 arch/arm64/kernel/entry-common.c:522 softirqs last enabled at (58378): [] softirq_handle_end kernel/softirq.c:468 [inline] softirqs last enabled at (58378): [] handle_softirqs+0xbc4/0xd34 kernel/softirq.c:650 softirqs last disabled at (58289): [] __do_softirq+0x14/0x20 kernel/softirq.c:656 CPU: 0 UID: 0 PID: 9857 Comm: syz.9.920 Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 pstate: 63400005 (nZCv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : csd_lock_wait kernel/smp.c:342 [inline] pc : smp_call_function_many_cond+0xfa4/0x1614 kernel/smp.c:892 lr : csd_lock_wait kernel/smp.c:342 [inline] lr : smp_call_function_many_cond+0xfbc/0x1614 kernel/smp.c:892 sp : ffff8000901d72e0 x29: ffff8000901d73f0 x28: dfff800000000000 x27: ffff0001a5fd0780 x26: 0000000000000011 x25: 0000000000000001 x24: ffff80008897f680 x23: ffffffffffffffff x22: 1fffe00034bfa0f0 x21: 1fffe00034bfa0f1 x20: ffff0001a5ffa0a8 x19: ffff0001a5fd0788 x18: 0000000000000000 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000000 x14: 00000000ffff8000 x13: 0000000000000001 x12: 0000000000000000 x11: 0000000000000000 x10: 0000000000080000 x9 : 0000000000000000 x8 : 0000000000000011 x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000001 x4 : 0000000000000000 x3 : ffff8000805a47c4 x2 : 0000000000000000 x1 : ffff0000daea0000 x0 : 0000000000000001 Call trace: __cmpwait_case_32 arch/arm64/include/asm/cmpxchg.h:233 [inline] (P) __cmpwait arch/arm64/include/asm/cmpxchg.h:259 [inline] (P) csd_lock_wait kernel/smp.c:342 [inline] (P) smp_call_function_many_cond+0xfa4/0x1614 kernel/smp.c:892 (P) smp_call_function_many kernel/smp.c:915 [inline] smp_call_function+0x58/0xbc kernel/smp.c:935 kick_all_cpus_sync+0x28/0x34 kernel/smp.c:1081 flush_icache_range arch/arm64/include/asm/cacheflush.h:105 [inline] __text_poke+0xd4/0xf4 arch/arm64/kernel/patching.c:129 aarch64_insn_copy+0x3c/0x50 arch/arm64/kernel/patching.c:160 bpf_arch_text_copy+0x34/0x54 arch/arm64/net/bpf_jit_comp.c:2234 bpf_jit_binary_pack_finalize+0x44/0xf0 kernel/bpf/core.c:1179 bpf_int_jit_compile+0xc40/0xffc arch/arm64/net/bpf_jit_comp.c:2164 bpf_prog_jit_compile kernel/bpf/core.c:2561 [inline] __bpf_prog_select_runtime+0x34c/0x684 kernel/bpf/core.c:2630 bpf_check+0x2c4c/0x3c88 kernel/bpf/verifier.c:20189 bpf_prog_load+0xf40/0x1434 kernel/bpf/syscall.c:3082 __sys_bpf+0x3f4/0x5f0 kernel/bpf/syscall.c:6274 __do_sys_bpf kernel/bpf/syscall.c:6387 [inline] __se_sys_bpf kernel/bpf/syscall.c:6385 [inline] __arm64_sys_bpf+0x80/0x98 kernel/bpf/syscall.c:6385 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0xe8/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 100 PID: 4395 Comm: dhcpcd Tainted: G L syzkaller #0 PREEMPT Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 pstate: 83400005 (Nzcv daif +PAN -UAO +TCO +DIT -SSBS BTYPE=--) pc : handle_softirqs+0x1d0/0xd34 kernel/softirq.c:610 lr : handle_softirqs+0x1cc/0xd34 kernel/softirq.c:606 sp : ffff80008e997ee0 x29: ffff80008e997f80 x28: ffff0000c8ab3a10 x27: 0000000000000186 x26: ffff0000c8ab3a08 x25: 1fffe00019156741 x24: ffff800097237a40 x23: ffff0000c8ab3a00 x22: dfff800000000000 x21: ffff0001a5ff3480 x20: ffff80008891febc x19: ffff0001a5ff3480 x18: 0000000000000000 x17: ffff80011d6bf000 x16: ffff80008e990000 x15: 0000000000000000 x14: 0000508077721080 x13: 0000000000000001 x12: 0000000000000000 x11: ffff80008a3f4d08 x10: 0000000000000003 x9 : 0000000000000000 x8 : 000000000005824a x7 : 0000000000000000 x6 : 0000000000000000 x5 : 0000000000000001 x4 : 0000000000000008 x3 : ffff800080155224 x2 : 0000000000000002 x1 : ffff0000c8ab3a00 x0 : ffff80011d6bf000 Call trace: __daif_local_irq_enable arch/arm64/include/asm/irqflags.h:26 [inline] (P) arch_local_irq_enable arch/arm64/include/asm/irqflags.h:48 [inline] (P) handle_softirqs+0x1d0/0xd34 kernel/softirq.c:606 (P) __do_softirq+0x14/0x20 kernel/softirq.c:656 ____do_softirq+0x14/0x20 arch/arm64/kernel/irq.c:78 call_on_irq_stack+0x30/0x48 arch/arm64/kernel/entry.S:889 do_softirq_own_stack+0x20/0x2c arch/arm64/kernel/irq.c:83 invoke_softirq kernel/softirq.c:503 [inline] __irq_exit_rcu+0x1ac/0x428 kernel/softirq.c:735 irq_exit_rcu+0x14/0x84 kernel/softirq.c:752 __el1_irq arch/arm64/kernel/entry-common.c:510 [inline] el1_interrupt+0x40/0x60 arch/arm64/kernel/entry-common.c:522 el1h_64_irq_handler+0x18/0x24 arch/arm64/kernel/entry-common.c:527 el1h_64_irq+0x6c/0x70 arch/arm64/kernel/entry.S:590 kunwind_next_frame_record arch/arm64/kernel/stacktrace.c:232 [inline] (P) kunwind_next arch/arm64/kernel/stacktrace.c:266 [inline] (P) do_kunwind arch/arm64/kernel/stacktrace.c:295 [inline] (P) kunwind_stack_walk arch/arm64/kernel/stacktrace.c:366 [inline] (P) arch_stack_walk+0x23c/0x328 arch/arm64/kernel/stacktrace.c:390 (P) stack_trace_save+0x9c/0xf0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x40/0x78 mm/kasan/common.c:78 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x74/0xa4 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6251 [inline] kmem_cache_free+0x184/0x6b8 mm/slub.c:6378 kfree_skbmem+0x14c/0x1d8 net/core/skbuff.c:-1 __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb+0x88/0xf4 net/core/skbuff.c:1436 skb_free_datagram+0x20/0x30 net/core/datagram.c:324 __unix_dgram_recvmsg+0x654/0x898 net/unix/af_unix.c:2669 unix_dgram_recvmsg+0xcc/0xe4 net/unix/af_unix.c:2686 unix_seqpacket_recvmsg+0x9c/0xcc net/unix/af_unix.c:2553 sock_recvmsg_nosec net/socket.c:1137 [inline] sock_recvmsg+0xd8/0x134 net/socket.c:1159 sock_read_iter+0x1ec/0x2a8 net/socket.c:1229 do_iter_readv_writev+0x48c/0x6f8 fs/read_write.c:-1 vfs_readv+0x234/0x588 fs/read_write.c:1020 do_readv+0x134/0x2a4 fs/read_write.c:1082 __do_sys_readv fs/read_write.c:1167 [inline] __se_sys_readv fs/read_write.c:1164 [inline] __arm64_sys_readv+0x80/0x94 fs/read_write.c:1164 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x198/0x23c arch/arm64/kernel/syscall.c:121 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:140 el0_svc+0x64/0x260 arch/arm64/kernel/entry-common.c:736 el0t_64_sync_handler+0x48/0x148 arch/arm64/kernel/entry-common.c:755 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:594