From: syzbot <syzbot+7590ddacf9f333c18f6c@syzkaller.appspotmail.com>
To: axboe@kernel.dk, bp@alien8.de, hpa@zytor.com, jack@suse.cz,
jmattson@google.com, joro@8bytes.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, mingo@redhat.com,
paolo.valente@linaro.org, pbonzini@redhat.com, seanjc@google.com,
syzkaller-bugs@googlegroups.com, tglx@linutronix.de,
vkuznets@redhat.com, wanpengli@tencent.com, x86@kernel.org
Subject: Re: [syzbot] general protection fault in rcu_segcblist_enqueue
Date: Sat, 14 Aug 2021 01:05:19 -0700 [thread overview]
Message-ID: <000000000000d49b4e05c9806d11@google.com> (raw)
In-Reply-To: <00000000000084943605c64a9cbd@google.com>
syzbot has found a reproducer for the following issue on:
HEAD commit: 4b358aabb93a Add linux-next specific files for 20210813
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=13fb40f9300000
kernel config: https://syzkaller.appspot.com/x/.config?x=b99612666fbe2d6a
dashboard link: https://syzkaller.appspot.com/bug?extid=7590ddacf9f333c18f6c
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.1
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12b34781300000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10249f79300000
The issue was bisected to:
commit 71217df39dc67a0aeed83352b0d712b7892036a2
Author: Paolo Valente <paolo.valente@linaro.org>
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@syzkaller.appspotmail.com
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: 8358 Comm: syz-executor858 Not tainted 5.14.0-rc5-next-20210813-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:ffffc90002d1fbe0 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880b9c00080 RCX: ffffffff815b8cb0
RDX: 0000000000000000 RSI: ffffc90002d1fcc8 RDI: ffff8880b9c000a0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000003
R10: fffff520005a3f6e R11: 0000000000000000 R12: ffffc90002d1fcc8
R13: ffff8880b9c00080 R14: 0000000000000000 R15: ffff8880b9c00040
FS: 00007f6a0b6c7700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004d2700 CR3: 0000000073719000 CR4: 00000000001526f0
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:823
__call_srcu kernel/rcu/srcutree.c:883 [inline]
__synchronize_srcu+0x21f/0x290 kernel/rcu/srcutree.c:929
kvm_mmu_uninit_vm+0x18/0x30 arch/x86/kvm/mmu/mmu.c:5625
kvm_arch_destroy_vm+0x4e7/0x680 arch/x86/kvm/x86.c:11317
kvm_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:1075 [inline]
kvm_dev_ioctl_create_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:4548 [inline]
kvm_dev_ioctl+0xfe6/0x1a40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4603
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:874 [inline]
__se_sys_ioctl fs/ioctl.c:860 [inline]
__x64_sys_ioctl+0x193/0x200 fs/ioctl.c:860
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: 0033:0x446a69
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 a1 15 00 00 90 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6a0b6c7278 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004cb4d0 RCX: 0000000000446a69
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000003
RBP: 00000000004cb4dc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000049b2a8
R13: 00007f6a0b6c7280 R14: 6d766b2f7665642f R15: 00000000004cb4d8
Modules linked in:
---[ end trace 87a789ef23d34c4d ]---
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:ffffc90002d1fbe0 EFLAGS: 00010046
RAX: dffffc0000000000 RBX: ffff8880b9c00080 RCX: ffffffff815b8cb0
RDX: 0000000000000000 RSI: ffffc90002d1fcc8 RDI: ffff8880b9c000a0
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000003
R10: fffff520005a3f6e R11: 0000000000000000 R12: ffffc90002d1fcc8
R13: ffff8880b9c00080 R14: 0000000000000000 R15: ffff8880b9c00040
FS: 00007f6a0b6c7700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000004d2700 CR3: 0000000073719000 CR4: 00000000001526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess), 7 bytes skipped:
0: df 48 89 fisttps -0x77(%rax)
3: fa cli
4: 48 c1 ea 03 shr $0x3,%rdx
8: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1)
c: 75 4e jne 0x5c
e: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax
15: fc ff df
18: 48 8b 6b 20 mov 0x20(%rbx),%rbp
1c: 48 89 ea mov %rbp,%rdx
1f: 48 c1 ea 03 shr $0x3,%rdx
23: 80 3c 02 00 cmpb $0x0,(%rdx,%rax,1) <-- trapping instruction
27: 75 21 jne 0x4a
29: 48 89 75 00 mov %rsi,0x0(%rbp)
2d: 48 89 73 20 mov %rsi,0x20(%rbx)
31: 48 83 c4 08 add $0x8,%rsp
35: 5b pop %rbx
36: 5d pop %rbp
37: c3 retq
38: 48 rex.W
next prev parent reply other threads:[~2021-08-14 8:05 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-04 11:37 [syzbot] general protection fault in rcu_segcblist_enqueue syzbot
2021-08-14 8:05 ` syzbot [this message]
2021-10-06 22:49 ` syzbot
2021-10-06 22:52 ` Sean Christopherson
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