WARNING in switch_fpu_return

From: syzbot
Date: Wed Jan 01 2020 - 21:25:16 EST


Hello,

syzbot found the following crash on:

HEAD commit: bf8d1cd4 Merge tag 'scsi-fixes' of git://git.kernel.org/pu..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17a4ce15e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=ed9d672709340e35
dashboard link: https://syzkaller.appspot.com/bug?extid=f2ca20d4aa1408b0385a
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
userspace arch: i386
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10cc8971e00000

The bug was bisected to:

commit 92e6475ae0a0383b012eb21c1aaf0e5456b1a3d9
Author: Nicholas Kazlauskas <nicholas.kazlauskas@xxxxxxx>
Date: Wed Jul 3 14:02:39 2019 +0000

drm/amd/display: Set enabled to false at start of audio disable

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=15614e3ee00000
console output: https://syzkaller.appspot.com/x/log.txt?x=13614e3ee00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+f2ca20d4aa1408b0385a@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 92e6475ae0a0 ("drm/amd/display: Set enabled to false at start of audio disable")

------------[ cut here ]------------
WARNING: CPU: 0 PID: 2862 at arch/x86/include/asm/fpu/internal.h:539 __fpregs_load_activate arch/x86/include/asm/fpu/internal.h:539 [inline]
WARNING: CPU: 0 PID: 2862 at arch/x86/include/asm/fpu/internal.h:539 switch_fpu_return+0x437/0x4f0 arch/x86/kernel/fpu/core.c:343
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 2862 Comm: kworker/0:3 Not tainted 5.5.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events async_pf_execute
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x197/0x210 lib/dump_stack.c:118
panic+0x2e3/0x75c kernel/panic.c:221
__warn.cold+0x2f/0x3e kernel/panic.c:582
report_bug+0x289/0x300 lib/bug.c:195
fixup_bug arch/x86/kernel/traps.c:174 [inline]
fixup_bug arch/x86/kernel/traps.c:169 [inline]
do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:__fpregs_load_activate arch/x86/include/asm/fpu/internal.h:539 [inline]
RIP: 0010:switch_fpu_return+0x437/0x4f0 arch/x86/kernel/fpu/core.c:343
Code: 0f 94 c6 31 ff 44 89 f6 e8 06 8f 4a 00 45 84 f6 0f 84 7f fd ff ff e8 b8 8d 4a 00 e8 a4 c9 d5 ff e9 70 fd ff ff e8 a9 8d 4a 00 <0f> 0b e9 b6 fd ff ff e8 9d 8d 4a 00 0f 0b e9 18 fd ff ff e8 91 8d
RSP: 0018:ffffc90007ecfa80 EFLAGS: 00010293
RAX: ffff88809f60e0c0 RBX: ffff88809f60e0c0 RCX: ffffffff812a9ccf
RDX: 0000000000000000 RSI: ffffffff812aa047 RDI: 0000000000000005
RBP: ffffc90007ecfb10 R08: ffff88809f60e0c0 R09: ffffed1013ec1c19
R10: ffffed1013ec1c18 R11: ffff88809f60e0c7 R12: 1ffff92000fd9f51
R13: ffff88809f60f5c0 R14: 0000000000200000 R15: ffffc90007ecfae8
kvm_arch_vcpu_load+0x66e/0x950 arch/x86/kvm/x86.c:3463
vcpu_load+0x43/0x90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:201
kvm_unload_vcpu_mmu arch/x86/kvm/x86.c:9543 [inline]
kvm_free_vcpus arch/x86/kvm/x86.c:9558 [inline]
kvm_arch_destroy_vm+0x184/0x5f0 arch/x86/kvm/x86.c:9663
kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:816 [inline]
kvm_put_kvm+0x5a5/0xcc0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:837
async_pf_execute+0x3bf/0x800 arch/x86/kvm/../../../virt/kvm/async_pf.c:101
process_one_work+0x9af/0x1740 kernel/workqueue.c:2264
worker_thread+0x98/0xe40 kernel/workqueue.c:2410
kthread+0x361/0x430 kernel/kthread.c:255
ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Kernel Offset: disabled
Rebooting in 86400 seconds..


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