Hello,
syzbot found the following issue on:
HEAD commit:92188b41 Merge tag 'perf-tools-fixes-2020-07-19' of git://..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=173963eb10
kernel config: https://syzkaller.appspot.com/x/.config?x=a160d1053fc89af5
dashboard link: https://syzkaller.appspot.com/bug?extid=e7a125aff38791d8cb65
compiler: gcc (GCC) 10.1.0-syz 20200507
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=178d601710
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=1688add710
The issue was bisected to:
commit dbfb089d360b1cc623c51a2c7cf9b99eff78e0e7
Author: Peter Zijlstra
Date: Fri Jul 3 10:40:33 2020 +
sched: Fix loadavg accounting race
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14e3af6f10
final oops: https://syzkaller.appspot.com/x/report.txt?x=16e3af6f10
console output: https://syzkaller.appspot.com/x/log.txt?x=12e3af6f10
IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+e7a125aff38791d8c...@syzkaller.appspotmail.com
Fixes: dbfb089d360b ("sched: Fix loadavg accounting race")
[ cut here ]
do not call blocking ops when !TASK_RUNNING; state=8 set at
[<076362f5>] ptrace_stop+0x0/0x9e0 kernel/signal.c:2054
WARNING: CPU: 1 PID: 17054 at kernel/sched/core.c:6883
__might_sleep+0x135/0x190 kernel/sched/core.c:6883
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 17054 Comm: syz-executor692 Not tainted 5.8.0-rc5-syzkaller #0
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+0x18f/0x20d lib/dump_stack.c:118
panic+0x2e3/0x75c kernel/panic.c:231
__warn.cold+0x20/0x45 kernel/panic.c:600
report_bug+0x1bd/0x210 lib/bug.c:198
handle_bug+0x38/0x90 arch/x86/kernel/traps.c:235
exc_invalid_op+0x13/0x40 arch/x86/kernel/traps.c:255
asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:540
RIP: 0010:__might_sleep+0x135/0x190 kernel/sched/core.c:6883
Code: 65 48 8b 1c 25 00 ff 01 00 48 8d 7b 10 48 89 fe 48 c1 ee 03 80 3c 06 00
75 2b 48 8b 73 10 48 c7 c7 a0 3f 4b 88 e8 2d 1a f5 ff <0f> 0b e9 46 ff ff ff e8
3f 40 63 00 e9 29 ff ff ff e8 35 40 63 00
RSP: 0018:c9000df87c78 EFLAGS: 00010282
RAX: RBX: 888095b3 RCX:
RDX: 888095b3 RSI: 815d4eb7 RDI: f52001bf0f81
RBP: 884ab220 R08: 0001 R09: 8880ae7318e7
R10: R11: R12: 0039
R13: R14: R15: 888095b30488
try_to_freeze_unsafe include/linux/freezer.h:57 [inline]
try_to_freeze include/linux/freezer.h:67 [inline]
freezer_count include/linux/freezer.h:128 [inline]
freezable_schedule include/linux/freezer.h:173 [inline]
ptrace_stop+0x4e2/0x9e0 kernel/signal.c:2215
ptrace_signal kernel/signal.c:2490 [inline]
get_signal+0xddc/0x1ee0 kernel/signal.c:2639
do_signal+0x82/0x2520 arch/x86/kernel/signal.c:810
exit_to_usermode_loop arch/x86/entry/common.c:235 [inline]
__prepare_exit_to_usermode+0x156/0x1f0 arch/x86/entry/common.c:269
do_syscall_64+0x6c/0xe0 arch/x86/entry/common.c:393
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x441729
Code: Bad RIP value.
RSP: 002b:7ffd1cbad2b8 EFLAGS: 0246 ORIG_RAX: 003d
RAX: fe00 RBX: RCX: 00441729
RDX: 8000 RSI: RDI:
RBP: 0017df84 R08: R09:
R10: R11: 0246 R12: 00402420
R13: 004024b0 R14: R15:
Kernel Offset: disabled
Rebooting in 86400 seconds..
---
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For information about bisection process see: https://goo.gl/tpsmEJ#bisection
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