[syzbot] general protection fault in rcu_segcblist_enqueue

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit:    df04fbe8 Merge branch 'for-linus' of git://git.kernel.org/..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13eb6594300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9a9c38351af1345a
dashboard link: https://syzkaller.appspot.com/bug?extid=7590ddacf9f333c18f6c
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1326068c300000

The issue was bisected to:

commit 71217df39dc67a0aeed83352b0d712b7892036a2
Author: Paolo Valente <paolo.valente@xxxxxxxxxx>
Date:   Mon Jan 25 19:02:48 2021 +0000

    block, bfq: make waker-queue detection more robust

bisection log:  https://syzkaller.appspot.com/x/bisect.txt?x=127c2700300000
final oops:     https://syzkaller.appspot.com/x/report.txt?x=117c2700300000
console output: https://syzkaller.appspot.com/x/log.txt?x=167c2700300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+7590ddacf9f333c18f6c@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 71217df39dc6 ("block, bfq: make waker-queue detection more robust")

general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 11479 Comm: syz-executor.0 Tainted: G        W         5.13.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:rcu_segcblist_enqueue+0xb9/0x130 kernel/rcu/rcu_segcblist.c:348
Code: 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4e 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 20 48 89 ea 48 c1 ea 03 <80> 3c 02 00 75 21 48 89 75 00 48 89 73 20 48 83 c4 08 5b 5d c3 48
RSP: 0018:ffffc90003287be8 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880b9c00080 RCX: ffffffff815c5540
RDX: 0000000000000000 RSI: ffffc90003287cd0 RDI: ffff8880b9c000a0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52000650f6f R11: 0000000000000000 R12: ffffc90003287cd0
R13: ffff8880b9c00080 R14: 0000000000000000 R15: ffff8880b9c00040
FS:  00007fbfbe427700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000544038 CR3: 000000003a8e9000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 srcu_gp_start_if_needed+0x116/0xbc0 kernel/rcu/srcutree.c:828
 __call_srcu kernel/rcu/srcutree.c:888 [inline]
 __synchronize_srcu+0x1d1/0x280 kernel/rcu/srcutree.c:934
 kvm_mmu_uninit_vm+0x18/0x30 arch/x86/kvm/mmu/mmu.c:5555
 kvm_arch_destroy_vm+0x4fc/0x690 arch/x86/kvm/x86.c:11265
 kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1046 [inline]
 kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4443 [inline]
 kvm_dev_ioctl+0x120e/0x1740 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4498
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:1069 [inline]
 __se_sys_ioctl fs/ioctl.c:1055 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:1055
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x4665d9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fbfbe427188 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 000000000056bf80 RCX: 00000000004665d9
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000003
RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000056bf80
R13: 00007ffc6c46097f R14: 00007fbfbe427300 R15: 0000000000022000
Modules linked in:
---[ end trace e798d58b3973533f ]---
RIP: 0010:rcu_segcblist_enqueue+0xb9/0x130 kernel/rcu/rcu_segcblist.c:348
Code: 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 4e 48 b8 00 00 00 00 00 fc ff df 48 8b 6b 20 48 89 ea 48 c1 ea 03 <80> 3c 02 00 75 21 48 89 75 00 48 89 73 20 48 83 c4 08 5b 5d c3 48
RSP: 0018:ffffc90003287be8 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880b9c00080 RCX: ffffffff815c5540
RDX: 0000000000000000 RSI: ffffc90003287cd0 RDI: ffff8880b9c000a0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52000650f6f R11: 0000000000000000 R12: ffffc90003287cd0
R13: ffff8880b9c00080 R14: 0000000000000000 R15: ffff8880b9c00040
FS:  00007fbfbe427700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000544038 CR3: 000000003a8e9000 CR4: 00000000001506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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