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BUG: KASAN: slab-out-of-bounds in predicate_parse kernel/trace/trace_events_filter.c:562 [inline]
BUG: KASAN: slab-out-of-bounds in process_preds+0x1905/0x19d0 kernel/trace/trace_events_filter.c:1505
Read of size 4 at addr ffff8801af622ff0 by task syz-executor4/20486

CPU: 0 PID: 20486 Comm: syz-executor4 Not tainted 4.17.0-rc3+ #3
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+0x242/0x2fe mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 predicate_parse kernel/trace/trace_events_filter.c:562 [inline]
 process_preds+0x1905/0x19d0 kernel/trace/trace_events_filter.c:1505
 create_filter+0x155/0x270 kernel/trace/trace_events_filter.c:1713
 ftrace_profile_set_filter+0x130/0x2e0 kernel/trace/trace_events_filter.c:2038
 perf_event_set_filter+0x248/0x1230 kernel/events/core.c:9079
 _perf_ioctl+0x84c/0x15e0 kernel/events/core.c:5059
 perf_ioctl+0x59/0x80 kernel/events/core.c:5110
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:500 [inline]
 do_vfs_ioctl+0x1cf/0x16a0 fs/ioctl.c:684
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:701
 __do_sys_ioctl fs/ioctl.c:708 [inline]
 __se_sys_ioctl fs/ioctl.c:706 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:706
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x455979
RSP: 002b:00007f375e657c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f375e6586d4 RCX: 0000000000455979
RDX: 0000000020000040 RSI: 0000000040082406 RDI: 0000000000000013
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000000002bf R14: 00000000006f8288 R15: 0000000000000000

Allocated by task 8505:
 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
 __do_kmalloc mm/slab.c:3718 [inline]
 __kmalloc_track_caller+0x14a/0x760 mm/slab.c:3733
 kstrdup+0x39/0x70 mm/util.c:56
 kstrdup_const+0x66/0x80 mm/util.c:77
 alloc_vfsmnt+0x1b3/0x9d0 fs/namespace.c:214
 clone_mnt+0x11c/0x1480 fs/namespace.c:1077
 copy_tree+0x46c/0xae0 fs/namespace.c:1806
 propagate_one+0x4db/0x910 fs/pnode.c:265
 propagate_mnt+0x18a/0x3e0 fs/pnode.c:315
 attach_recursive_mnt+0x5f8/0xb50 fs/namespace.c:2033
 graft_tree+0x1aa/0x240 fs/namespace.c:2133
 do_loopback fs/namespace.c:2254 [inline]
 do_mount+0x2745/0x3070 fs/namespace.c:2842
 ksys_mount+0x12d/0x140 fs/namespace.c:3064
 __do_sys_mount fs/namespace.c:3078 [inline]
 __se_sys_mount fs/namespace.c:3075 [inline]
 __x64_sys_mount+0xbe/0x150 fs/namespace.c:3075
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 17:
 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]
 kfree+0xd9/0x260 mm/slab.c:3813
 kfree_const+0x59/0x70 mm/util.c:38
 free_vfsmnt+0x37/0x80 fs/namespace.c:640
 delayed_free_vfsmnt+0x16/0x20 fs/namespace.c:649
 __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 ffff8801af622f80
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 80 bytes to the right of
 32-byte region [ffff8801af622f80, ffff8801af622fa0)
The buggy address belongs to the page:
page:ffffea0006bd8880 count:1 mapcount:0 mapping:ffff8801af622000 index:0xffff8801af622fc1
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801af622000 ffff8801af622fc1 0000000100000001
raw: ffffea0006c508e0 ffffea0006be07e0 ffff8801da8001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801af622e80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801af622f00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801af622f80: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc
                                                             ^
 ffff8801af623000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801af623080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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