==================================================================
BUG: KASAN: use-after-free in uprobe_perf_close+0x45e/0x5f0 kernel/trace/trace_uprobe.c:1048
Read of size 4 at addr ffff8801c000e24c by task syz-executor2/11815

CPU: 0 PID: 11815 Comm: syz-executor2 Not tainted 4.16.0+ #4
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+0x1b9/0x294 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+0xac/0x2f5 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 uprobe_perf_close+0x45e/0x5f0 kernel/trace/trace_uprobe.c:1048
 trace_uprobe_register+0x355/0xcd0 kernel/trace/trace_uprobe.c:1210
 perf_trace_event_close kernel/trace/trace_event_perf.c:186 [inline]
 perf_uprobe_destroy+0xa0/0x130 kernel/trace/trace_event_perf.c:335
 _free_event+0x3ff/0x13b0 kernel/events/core.c:4445
 put_event+0x48/0x60 kernel/events/core.c:4528
 perf_event_release_kernel+0x8bd/0xf90 kernel/events/core.c:4634
 perf_release+0x37/0x50 kernel/events/core.c:4644
 __fput+0x34d/0x890 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x1e4/0x290 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x1aee/0x2730 kernel/exit.c:865
 do_group_exit+0x16f/0x430 kernel/exit.c:968
 SYSC_exit_group kernel/exit.c:979 [inline]
 SyS_exit_group+0x1d/0x20 kernel/exit.c:977
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x455259
RSP: 002b:0000000000a3ea98 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 000000000000046f RCX: 0000000000455259
RDX: 000000000000007d RSI: 0000000000732578 RDI: 0000000000000000
RBP: 00000000ffffffff R08: 000000000000003f R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000013
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000001380

Allocated by task 11815:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xc4/0xe0 mm/kasan/kasan.c:552
 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
 slab_post_alloc_hook mm/slab.h:443 [inline]
 slab_alloc_node mm/slab.c:3323 [inline]
 kmem_cache_alloc_node+0x131/0x780 mm/slab.c:3630
 alloc_task_struct_node kernel/fork.c:157 [inline]
 dup_task_struct kernel/fork.c:770 [inline]
 copy_process.part.39+0x16bf/0x6ee0 kernel/fork.c:1631
 copy_process kernel/fork.c:1606 [inline]
 _do_fork+0x291/0x12a0 kernel/fork.c:2087
 SYSC_clone kernel/fork.c:2194 [inline]
 SyS_clone+0x37/0x50 kernel/fork.c:2188
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7

Freed by task 0:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 __kasan_slab_free+0x11a/0x170 mm/kasan/kasan.c:520
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:527
 __cache_free mm/slab.c:3486 [inline]
 kmem_cache_free+0x86/0x2d0 mm/slab.c:3744
 free_task_struct kernel/fork.c:162 [inline]
 free_task+0x166/0x1d0 kernel/fork.c:391
 __put_task_struct+0x2d2/0x600 kernel/fork.c:657
 put_task_struct include/linux/sched/task.h:96 [inline]
 delayed_put_task_struct+0x367/0x470 kernel/exit.c:180
 __rcu_reclaim kernel/rcu/rcu.h:178 [inline]
 rcu_do_batch kernel/rcu/tree.c:2675 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2930 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2897 [inline]
 rcu_process_callbacks+0x941/0x15f0 kernel/rcu/tree.c:2914
 __do_softirq+0x2e0/0xaf5 kernel/softirq.c:285

The buggy address belongs to the object at ffff8801c000e200
 which belongs to the cache task_struct(113:syz2) of size 6016
The buggy address is located 76 bytes inside of
 6016-byte region [ffff8801c000e200, ffff8801c000f980)
The buggy address belongs to the page:
page:ffffea0007000380 count:1 mapcount:0 mapping:ffff8801c000e200 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000008100(slab|head)
raw: 02fffc0000008100 ffff8801c000e200 0000000000000000 0000000100000001
raw: ffffea0006c3c320 ffffea0006add620 ffff8801bb2e76c0 ffff8801d7cb6a00
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8801d7cb6a00

Memory state around the buggy address:
 ffff8801c000e100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801c000e180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8801c000e200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff8801c000e280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801c000e300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================