syzbot

==================================================================
BUG: KASAN: use-after-free in primary_event_id kernel/events/core.c:1315 [inline]
BUG: KASAN: use-after-free in perf_output_read_group kernel/events/core.c:5893 [inline]
BUG: KASAN: use-after-free in perf_output_read+0x1046/0x1090 kernel/events/core.c:5928
Read of size 8 at addr ffff88808b306620 by task syz-executor.0/25992

CPU: 1 PID: 25992 Comm: syz-executor.0 Not tainted 4.14.193-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x1b2/0x283 lib/dump_stack.c:58
 print_address_description.cold+0x54/0x1d3 mm/kasan/report.c:252
 kasan_report_error.cold+0x8a/0x194 mm/kasan/report.c:351
 kasan_report mm/kasan/report.c:409 [inline]
 __asan_report_load8_noabort+0x68/0x70 mm/kasan/report.c:430
 primary_event_id kernel/events/core.c:1315 [inline]
 perf_output_read_group kernel/events/core.c:5893 [inline]
 perf_output_read+0x1046/0x1090 kernel/events/core.c:5928
 perf_output_sample+0xa28/0x16f0 kernel/events/core.c:5970
 __perf_event_output kernel/events/core.c:6283 [inline]
 perf_event_output_forward+0xf8/0x1f0 kernel/events/core.c:6296
 __perf_event_overflow+0x113/0x310 kernel/events/core.c:7541
 perf_swevent_overflow kernel/events/core.c:7617 [inline]
 perf_swevent_event+0x299/0x460 kernel/events/core.c:7645
 do_perf_sw_event kernel/events/core.c:7758 [inline]
 ___perf_sw_event+0x2a1/0x480 kernel/events/core.c:7789
 __perf_sw_event+0x4f/0x100 kernel/events/core.c:7801
 perf_sw_event include/linux/perf_event.h:1046 [inline]
 __do_page_fault+0x6c1/0xb50 arch/x86/mm/fault.c:1483
 page_fault+0x25/0x50 arch/x86/entry/entry_64.S:1123
RIP: 0010:copy_user_enhanced_fast_string+0xe/0x20 arch/x86/lib/copy_user_64.S:181
RSP: 0018:ffff888208a4fa78 EFLAGS: 00010206
RAX: ffffed10414cc000 RBX: 0000000000008000 RCX: 0000000000003acb
RDX: 0000000000008000 RSI: 0000000020ffa000 RDI: ffff88820a65c535
RBP: 0000000020ff5acb R08: 0000000000000001 R09: ffffed10414cbfff
R10: ffff88820a65ffff R11: 0000000000000000 R12: ffff88820a658000
R13: 00007ffffffff000 R14: 0000000020ffdacb R15: ffff88820a658000
 copy_user_generic arch/x86/include/asm/uaccess_64.h:37 [inline]
 raw_copy_from_user arch/x86/include/asm/uaccess_64.h:55 [inline]
 copyin+0x99/0xc0 lib/iov_iter.c:146
 _copy_from_iter_full+0x195/0x690 lib/iov_iter.c:608
 copy_from_iter_full include/linux/uio.h:126 [inline]
 skb_do_copy_data_nocache include/net/sock.h:1885 [inline]
 skb_copy_to_page_nocache include/net/sock.h:1911 [inline]
 tcp_sendmsg_locked+0x23fc/0x2ef0 net/ipv4/tcp.c:1360
 tcp_sendmsg+0x2b/0x40 net/ipv4/tcp.c:1457
 inet_sendmsg+0x11a/0x4e0 net/ipv4/af_inet.c:762
 sock_sendmsg_nosec net/socket.c:646 [inline]
 sock_sendmsg+0xb5/0x100 net/socket.c:656
 SYSC_sendto net/socket.c:1763 [inline]
 SyS_sendto+0x1c7/0x2c0 net/socket.c:1731
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb
RIP: 0033:0x45ccd9
RSP: 002b:00007f1c59073c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 000000000002c340 RCX: 000000000045ccd9
RDX: ffffffffffffffef RSI: 0000000020d7cfcb RDI: 0000000000000006
RBP: 000000000078bf58 R08: 0000000000000000 R09: 0000000000000053
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007ffc6c21c5ef R14: 00007f1c590749c0 R15: 000000000078bf0c

Allocated by task 25990:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xeb/0x160 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3720 [inline]
 __kmalloc+0x15a/0x400 mm/slab.c:3729
 kmalloc include/linux/slab.h:493 [inline]
 kzalloc include/linux/slab.h:661 [inline]
 rb_alloc+0x7e/0x4a0 kernel/events/ring_buffer.c:750
 perf_mmap+0xc13/0x1390 kernel/events/core.c:5478
 call_mmap include/linux/fs.h:1783 [inline]
 mmap_region+0xa1a/0x1220 mm/mmap.c:1717
 do_mmap+0x5b3/0xcb0 mm/mmap.c:1495
 do_mmap_pgoff include/linux/mm.h:2185 [inline]
 vm_mmap_pgoff+0x14e/0x1a0 mm/util.c:333
 SYSC_mmap_pgoff mm/mmap.c:1545 [inline]
 SyS_mmap_pgoff+0x249/0x510 mm/mmap.c:1503
 do_syscall_64+0x1d5/0x640 arch/x86/entry/common.c:292
 entry_SYSCALL_64_after_hwframe+0x46/0xbb

Freed by task 7:
 save_stack mm/kasan/kasan.c:447 [inline]
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0xc3/0x1a0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3496 [inline]
 kfree+0xc9/0x250 mm/slab.c:3815
 __rcu_reclaim kernel/rcu/rcu.h:195 [inline]
 rcu_do_batch kernel/rcu/tree.c:2699 [inline]
 invoke_rcu_callbacks kernel/rcu/tree.c:2962 [inline]
 __rcu_process_callbacks kernel/rcu/tree.c:2929 [inline]
 rcu_process_callbacks+0x780/0x1180 kernel/rcu/tree.c:2946
 __do_softirq+0x254/0xa1d kernel/softirq.c:288

The buggy address belongs to the object at ffff88808b3065c0
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 96 bytes inside of
 512-byte region [ffff88808b3065c0, ffff88808b3067c0)
The buggy address belongs to the page:
page:ffffea00022cc180 count:1 mapcount:0 mapping:ffff88808b3060c0 index:0x0
flags: 0xfffe0000000100(slab)
raw: 00fffe0000000100 ffff88808b3060c0 0000000000000000 0000000100000006
raw: ffffea0001518fe0 ffffea0002158120 ffff88812fe52940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808b306500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808b306580: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff88808b306600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff88808b306680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808b306700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================