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BUG: KASAN: stack-out-of-bounds in __read_once_size include/linux/compiler.h:188 [inline]
BUG: KASAN: stack-out-of-bounds in get_running_cputimer include/linux/sched/cputime.h:85 [inline]
BUG: KASAN: stack-out-of-bounds in account_group_system_time include/linux/sched/cputime.h:149 [inline]
BUG: KASAN: stack-out-of-bounds in account_system_index_time+0x512/0x5c0 kernel/sched/cputime.c:168
Read of size 1 at addr ffff88019a4d5ab8 by task syz-executor2/14589

CPU: 1 PID: 14589 Comm: syz-executor2 Not tainted 4.18.0-rc3+ #55
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x2b4 lib/dump_stack.c:113
 print_address_description+0x6c/0x20b mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.7+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:430
 __read_once_size include/linux/compiler.h:188 [inline]
 get_running_cputimer include/linux/sched/cputime.h:85 [inline]
 account_group_system_time include/linux/sched/cputime.h:149 [inline]
 account_system_index_time+0x512/0x5c0 kernel/sched/cputime.c:168
 account_system_time+0x7f/0xb0 kernel/sched/cputime.c:199
 account_process_tick+0x76/0x240 kernel/sched/cputime.c:498
 update_process_times+0x21/0x70 kernel/time/timer.c:1634
 tick_sched_handle+0x9f/0x180 kernel/time/tick-sched.c:164
 tick_sched_timer+0x45/0x130 kernel/time/tick-sched.c:1274
 __run_hrtimer kernel/time/hrtimer.c:1398 [inline]
 __hrtimer_run_queues+0x3eb/0x10c0 kernel/time/hrtimer.c:1460
 hrtimer_interrupt+0x2f3/0x750 kernel/time/hrtimer.c:1518
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline]
 smp_apic_timer_interrupt+0x165/0x730 arch/x86/kernel/apic/apic.c:1050
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:863
 </IRQ>

Allocated by task 4475:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x760 mm/slab.c:3554
 kmem_cache_zalloc include/linux/slab.h:697 [inline]
 copy_signal+0x175/0xc10 kernel/fork.c:1443
 copy_process.part.40+0x2137/0x7220 kernel/fork.c:1800
 copy_process kernel/fork.c:1616 [inline]
 _do_fork+0x291/0x12a0 kernel/fork.c:2099
 __do_sys_clone kernel/fork.c:2206 [inline]
 __se_sys_clone kernel/fork.c:2200 [inline]
 __x64_sys_clone+0xbf/0x150 kernel/fork.c:2200
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 13297:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kmem_cache_free+0x86/0x2d0 mm/slab.c:3756
 free_signal_struct kernel/fork.c:643 [inline]
 put_signal_struct kernel/fork.c:649 [inline]
 __put_task_struct+0x3cd/0x620 kernel/fork.c:663
 put_task_struct include/linux/sched/task.h:96 [inline]
 delayed_put_task_struct+0x37f/0x490 kernel/exit.c:180
 __rcu_reclaim kernel/rcu/rcu.h:178 [inline]
 rcu_do_batch kernel/rcu/tree.c:2558 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2818 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2785 [inline]
 rcu_process_callbacks+0xed5/0x1850 kernel/rcu/tree.c:2802
 __do_softirq+0x2e8/0xb17 kernel/softirq.c:288

The buggy address belongs to the object at ffff88019a4d5980
 which belongs to the cache signal_cache(49:syz2) of size 1296
The buggy address is located 312 bytes inside of
 1296-byte region [ffff88019a4d5980, ffff88019a4d5e90)
The buggy address belongs to the page:
page:ffffea0006693500 count:1 mapcount:0 mapping:ffff8801b4f2cc80 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea0006f0c008 ffffea0007473108 ffff8801b4f2cc80
raw: 0000000000000000 ffff88019a4d4280 0000000100000005 ffff8801d2e12180
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8801d2e12180

Memory state around the buggy address:
 ffff88019a4d5980: 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 f2 f2
 ffff88019a4d5a00: f2 f2 f2 f2 f2 00 f2 f2 f2 f2 f2 f2 f2 00 f2 f2
>ffff88019a4d5a80: f2 f2 f2 f2 f2 f8 f2 f2 f2 f2 f2 f2 f2 00 f2 f2
                                        ^
 ffff88019a4d5b00: f2 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88019a4d5b80: 00 00 00 00 00 00 f1 f1 f1 f1 00 f2 f2 f2 f2 f2
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