------------[ cut here ]------------
WARNING: CPU: 0 PID: 25637 at kernel/rcu/tree_stall.h:894 rcu_check_gp_start_stall.part.0+0x325/0x4b0 kernel/rcu/tree_stall.h:886
Modules linked in:
CPU: 0 PID: 25637 Comm: syz-executor.4 Not tainted 5.14.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rcu_check_gp_start_stall.part.0+0x325/0x4b0 kernel/rcu/tree_stall.h:894
Code: 0f 88 fa 00 00 00 be 04 00 00 00 48 c7 c7 60 15 22 90 e8 ee 1d 5a 00 b8 01 00 00 00 87 05 13 86 c0 0e 85 c0 0f 85 c9 00 00 00 <0f> 0b 48 81 fd 00 48 98 8b 48 c7 c3 ac 8b 6c 8d 74 58 48 b8 00 00
RSP: 0018:ffffc90000007e30 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 000000010004b32e RCX: ffffffff81618f42
RDX: fffffbfff20442ac RSI: 0000000000000004 RDI: ffffffff90221560
RBP: ffffffff8b984800 R08: 0000000000000001 R09: 0000000000000003
R10: fffffbfff20442ac R11: 0000000000000000 R12: 1ffffffff16c1e30
R13: 0000000000000246 R14: ffff8880b9c52912 R15: 0000000000000001
FS:  00007fe8f720b700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000208a6000 CR3: 00000000a281e000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 rcu_check_gp_start_stall kernel/rcu/tree_stall.h:857 [inline]
 rcu_core+0x4df/0x1380 kernel/rcu/tree.c:2780
 __do_softirq+0x29b/0x9c2 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x16e/0x1c0 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:finish_task_switch.isra.0+0x23c/0xa50 kernel/sched/core.c:4557
Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 e3 c3 dc 07 e8 3e e3 2b 00 fb 65 48 8b 1c 25 00 f0 01 00 <48> 8d bb 10 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc9001b7172d8 EFLAGS: 00000206
RAX: 000000000090745f RBX: ffff8880b3a43880 RCX: 1ffffffff1ad85a1
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9001b717318 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff817bac98 R11: 0000000000000000 R12: ffff8880b9c51a80
R13: ffff88801b648000 R14: ffff8880aa975400 R15: ffff8880b9c51a98
 context_switch kernel/sched/core.c:4686 [inline]
 __schedule+0x942/0x26f0 kernel/sched/core.c:5940
 preempt_schedule_common+0x45/0xc0 kernel/sched/core.c:6100
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 __kunmap_atomic include/linux/highmem-internal.h:203 [inline]
 clear_highpage include/linux/highmem.h:185 [inline]
 kernel_init_free_pages.part.0+0xff/0x120 mm/page_alloc.c:1283
 kernel_init_free_pages mm/page_alloc.c:1272 [inline]
 post_alloc_hook+0x145/0x1e0 mm/page_alloc.c:2423
 prep_new_page mm/page_alloc.c:2433 [inline]
 get_page_from_freelist+0xa72/0x2f80 mm/page_alloc.c:4166
 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5388
 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2244
 alloc_skb_with_frags+0x1b9/0x620 net/core/skbuff.c:6030
 sock_alloc_send_pskb+0x783/0x910 net/core/sock.c:2461
 unix_stream_sendmsg+0x62e/0x1020 net/unix/af_unix.c:1875
 sock_sendmsg_nosec net/socket.c:703 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:723
 ____sys_sendmsg+0x6e8/0x810 net/socket.c:2392
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2446
 __sys_sendmsg+0xe5/0x1b0 net/socket.c:2475
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665e9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fe8f720b188 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 000000000056c038 RCX: 00000000004665e9
RDX: 0000000000000000 RSI: 0000000020000e00 RDI: 0000000000000003
RBP: 00000000004bfcc4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056c038
R13: 00007ffc5096190f R14: 00007fe8f720b300 R15: 0000000000022000