Subject: WARNING in add_event_to_ctx

From: syzbot <[email-masked]>
Date: Thu, 20 Jun 2019 06:17:06 -0700

Hello,

syzbot found the following crash on:

HEAD commit:    abf02e29 Merge tag 'pm-5.2-rc6' of git://git.kernel.org/pu..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=129072e6a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=28ec3437a5394ee0
dashboard link: https://syzkaller.appspot.com/bug?extid=704bfe2c7d156640ad7a
compiler:       clang version 9.0.0 (/home/glider/llvm/clang  
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=16d8b732a00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=17f7a5e6a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email-masked]

WARNING: CPU: 0 PID: 8131 at kernel/events/core.c:1835 perf_group_attach  
kernel/events/core.c:1835 [inline]
WARNING: CPU: 0 PID: 8131 at kernel/events/core.c:1835  
add_event_to_ctx+0x1351/0x1630 kernel/events/core.c:2393
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8131 Comm: syz-executor982 Not tainted 5.2.0-rc5+ #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+0x1d8/0x2f8 lib/dump_stack.c:113
  panic+0x28a/0x7c9 kernel/panic.c:219
  __warn+0x216/0x220 kernel/panic.c:576
  report_bug+0x190/0x290 lib/bug.c:186
  fixup_bug arch/x86/kernel/traps.c:179 [inline]
  do_error_trap+0xd7/0x450 arch/x86/kernel/traps.c:272
  do_invalid_op+0x36/0x40 arch/x86/kernel/traps.c:291
  invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:986
RIP: 0010:perf_group_attach kernel/events/core.c:1835 [inline]
RIP: 0010:add_event_to_ctx+0x1351/0x1630 kernel/events/core.c:2393
Code: ff e8 d3 19 e6 ff 0f 0b e9 88 ed ff ff e8 c7 19 e6 ff 0f 0b e9 42 ed  
ff ff e8 bb 19 e6 ff 0f 0b e9 4f f8 ff ff e8 af 19 e6 ff <0f> 0b e9 d5 f8  
ff ff 48 c7 c1 a0 31 dd 88 80 e1 07 80 c1 03 38 c1
RSP: 0018:ffff888094cdf900 EFLAGS: 00010093
RAX: ffffffff818f9841 RBX: ffff888085d7c418 RCX: ffff888099a064c0
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffff888094cdf988 R08: ffffffff818f90aa R09: ffffed101299bf21
R10: ffffed101299bf20 R11: 1ffff1101299bf20 R12: dffffc0000000000
R13: ffff888085d7c200 R14: ffffe8ffffc15758 R15: ffff888085d7ca80
  __perf_install_in_context+0x54a/0x7e0 kernel/events/core.c:2544
  remote_function+0xeb/0x170 kernel/events/core.c:86
  generic_exec_single+0x114/0x420 kernel/smp.c:154
  smp_call_function_single+0x1a5/0x410 kernel/smp.c:300
  cpu_function_call kernel/events/core.c:140 [inline]
  perf_install_in_context+0x26b/0x5a0 kernel/events/core.c:2580
  __do_sys_perf_event_open kernel/events/core.c:11110 [inline]
  __se_sys_perf_event_open+0x224a/0x3270 kernel/events/core.c:10739
  __x64_sys_perf_event_open+0xbf/0xd0 kernel/events/core.c:10739
  do_syscall_64+0xfe/0x140 arch/x86/entry/common.c:301
  entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x446b69
Code: e8 8c 19 03 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 7b 0c fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f2b0c7bddb8 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00000000006dcc28 RCX: 0000000000446b69
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: 0000000020000000
RBP: 00000000006dcc20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 00000000006dcc2c
R13: 00007fff27b1f69f R14: 00007f2b0c7be9c0 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

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