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BUG: KASAN: use-after-free in is_idle_task include/linux/sched.h:1534 [inline]
BUG: KASAN: use-after-free in wake_up_if_idle+0x482/0x580 kernel/sched/core.c:1804
Read of size 4 at addr ffff88018899c464 by task syz-executor3/15576

CPU: 0 PID: 15576 Comm: syz-executor3 Not tainted 4.19.0-rc8+ #73
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c4/0x2b6 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 is_idle_task include/linux/sched.h:1534 [inline]
 wake_up_if_idle+0x482/0x580 kernel/sched/core.c:1804
 wake_up_all_idle_cpus+0x72/0xc0 kernel/smp.c:744
 cpuidle_latency_notify+0xe/0x20 drivers/cpuidle/cpuidle.c:666
 notifier_call_chain+0x17e/0x380 kernel/notifier.c:93
 __blocking_notifier_call_chain kernel/notifier.c:317 [inline]
 blocking_notifier_call_chain+0x147/0x190 kernel/notifier.c:328
 pm_qos_update_target+0x49a/0xd50 kernel/power/qos.c:316
 pm_qos_add_request+0x2b9/0x6f0 kernel/power/qos.c:460
 snd_pcm_hw_params+0x1a06/0x1f50 sound/core/pcm_native.c:760
 snd_pcm_kernel_ioctl+0x6c/0x220 sound/core/pcm_native.c:2984
 snd_pcm_oss_change_params_locked+0x1c0e/0x3c90 sound/core/oss/pcm_oss.c:993
 snd_pcm_oss_make_ready_locked+0xbc/0x130 sound/core/oss/pcm_oss.c:1183
 snd_pcm_oss_write1 sound/core/oss/pcm_oss.c:1397 [inline]
 snd_pcm_oss_write+0x51e/0xa40 sound/core/oss/pcm_oss.c:2775
 __vfs_write+0x119/0x9f0 fs/read_write.c:485
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457569
Code: fd b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007eff17388c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457569
RDX: 00000000fffffefd RSI: 00000000200000c0 RDI: 0000000000000006
RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007eff173896d4
R13: 00000000004c50b1 R14: 00000000004d8718 R15: 00000000ffffffff

Allocated by task 7929:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc_node+0x144/0x730 mm/slab.c:3644
 alloc_task_struct_node kernel/fork.c:157 [inline]
 dup_task_struct kernel/fork.c:802 [inline]
 copy_process+0x1ff4/0x8780 kernel/fork.c:1707
 _do_fork+0x1cb/0x11d0 kernel/fork.c:2166
 kernel_thread+0x34/0x40 kernel/fork.c:2225
 call_usermodehelper_exec_sync kernel/umh.c:130 [inline]
 call_usermodehelper_exec_work+0xc9/0x2f0 kernel/umh.c:182
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x420 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413

Freed by task 15580:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 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+0x83/0x290 mm/slab.c:3756
 free_task_struct kernel/fork.c:162 [inline]
 free_task+0x16e/0x1f0 kernel/fork.c:416
 __put_task_struct+0x2e6/0x620 kernel/fork.c:689
 put_task_struct include/linux/sched/task.h:96 [inline]
 finish_task_switch+0x628/0x910 kernel/sched/core.c:2709
 schedule_tail+0xe/0x130 kernel/sched/core.c:2771
 ret_from_fork+0x8/0x50 arch/x86/entry/entry_64.S:397

The buggy address belongs to the object at ffff88018899c440
 which belongs to the cache task_struct of size 6080
The buggy address is located 36 bytes inside of
 6080-byte region [ffff88018899c440, ffff88018899dc00)
The buggy address belongs to the page:
page:ffffea0006226700 count:1 mapcount:0 mapping:ffff8801da94c200 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffffea00070a3408 ffffea0006211c08 ffff8801da94c200
raw: 0000000000000000 ffff88018899c440 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88018899c300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88018899c380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88018899c400: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                       ^
 ffff88018899c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88018899c500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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