upstream test error: WARNING in __local_bh_enable_ip

syzbot
2020-08-05T07:19:32Z

Hello,

syzbot found the following issue on:

HEAD commit: 2324d50d Merge tag 'docs-5.9' of git://git.lwn.net/linux
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=16502632900000
kernel config: https://syzkaller.appspot.com/x/.config?x=b21ad52fca7be434
dashboard link: https://syzkaller.appspot.com/bug?extid=8db9e1ecde74e590a657
compiler: clang version 11.0.0 (https://github.com/llvm/llvm-project.git ca2dcbd030eadbf0aa9b660efe864ff08af6e18b)

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+8db9e1ecde74e590a657@syzkaller.appspotmail.com

------------[ cut here ]------------
WARNING: CPU: 1 PID: 8690 at kernel/softirq.c:175 __local_bh_enable_ip+0xdf/0x100 kernel/softirq.c:175
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 8690 Comm: syz-fuzzer Not tainted 5.8.0-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+0x16e/0x25d lib/dump_stack.c:118
panic+0x20c/0x69a kernel/panic.c:231
__warn+0x211/0x240 kernel/panic.c:600
report_bug+0x153/0x1d0 lib/bug.c:198
handle_bug+0x4d/0x90 arch/x86/kernel/traps.c:235
exc_invalid_op+0x16/0x70 arch/x86/kernel/traps.c:255
asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536
RIP: 0010:__local_bh_enable_ip+0xdf/0x100 kernel/softirq.c:175
Code: 00 00 65 8b 05 ae cd cf 7e 85 c0 75 05 e8 10 ae ce ff 5b 41 5e c3 0f 0b 83 3d 40 ee 2f 07 00 0f 85 49 ff ff ff e9 53 ff ff ff <0f> 0b e9 4c ff ff ff e8 15 00 00 00 eb aa 0f 0b 0f 0b 0f 1f 44 00
RSP: 0000:ffffc90000debd40 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff88811fc2a3c0
RDX: 0000000000000000 RSI: 0000000000000200 RDI: ffffffff811bf3f5
RBP: 0000000000000000 R08: 0000000000000000 R09: 000088811fc2b853
R10: 0000ffffffffffff R11: ffff88811fc2a3c0 R12: ffff88811fc2a3c0
R13: 000000c000099c80 R14: ffffffff811bf3f5 R15: ffff88811fc2b850
local_bh_enable+0x1b/0x20 include/linux/bottom_half.h:32
fpregs_unlock arch/x86/include/asm/fpu/api.h:41 [inline]
copy_fpstate_to_sigframe+0x2aa/0x5a0 arch/x86/kernel/fpu/signal.c:195
get_sigframe+0xf9/0x130 arch/x86/kernel/signal.c:274
__setup_rt_frame+0x56/0x310 arch/x86/kernel/signal.c:450
setup_rt_frame arch/x86/kernel/signal.c:702 [inline]
handle_signal arch/x86/kernel/signal.c:746 [inline]
arch_do_signal+0x1bd/0x270 arch/x86/kernel/signal.c:813
exit_to_user_mode_loop kernel/entry/common.c:135 [inline]
exit_to_user_mode_prepare+0x1bd/0x290 kernel/entry/common.c:166
irqentry_exit_to_user_mode+0x6/0x30 kernel/entry/common.c:254
irqentry_exit+0x23/0x80 kernel/entry/common.c:342
asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:538
RIP: 0033:0x467f53
Code: 00 48 81 eb 00 01 00 00 48 81 c7 00 01 00 00 48 81 fb 00 01 00 00 73 82 e9 07 ff ff ff c5 fd ef c0 48 81 fb 00 00 00 02 73 46 <c5> fe 7f 07 c5 fe 7f 47 20 c5 fe 7f 47 40 c5 fe 7f 47 60 48 81 eb
RSP: 002b:000000c00009fed8 EFLAGS: 00010202
RAX: 0000000000000000 RBX: 000000000000ce00 RCX: 0000000000000000
RDX: 00007f952f2dee00 RSI: 0000000000040000 RDI: 00007f952f2d2000
RBP: 000000c00009ff50 R08: 0000000000800000 R09: 00007f952f441fff
R10: 00007f952f086248 R11: 00000000000009cd R12: 00000000000003ff
R13: 0000000000000012 R14: 000080c000b9c000 R15: 000080c00139bfff
Kernel Offset: disabled
Rebooting in 86400 seconds..

---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.