* Re: [syzbot] INFO: task hung in synchronize_rcu (3)
[not found] <20220511132050.5868-1-hdanton@sina.com>
@ 2022-05-11 13:44 ` syzbot
0 siblings, 0 replies; 7+ messages in thread
From: syzbot @ 2022-05-11 13:44 UTC (permalink / raw)
To: hdanton, linux-kernel, syzkaller-bugs
Hello,
syzbot has tested the proposed patch and the reproducer did not trigger any issue:
Reported-and-tested-by: syzbot+0c6da80218456f1edc36@syzkaller.appspotmail.com
Tested on:
commit: 4fa640dc Merge tag 'vfio-v5.8-rc7' of git://github.com..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
kernel config: https://syzkaller.appspot.com/x/.config?x=c8387e9c623864db
dashboard link: https://syzkaller.appspot.com/bug?extid=0c6da80218456f1edc36
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch: https://syzkaller.appspot.com/x/patch.diff?x=163b1869f00000
Note: testing is done by a robot and is best-effort only.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in synchronize_rcu (3)
2022-05-10 13:50 ` Paolo Bonzini
@ 2022-05-10 13:56 ` Sean Christopherson
0 siblings, 0 replies; 7+ messages in thread
From: Sean Christopherson @ 2022-05-10 13:56 UTC (permalink / raw)
To: Paolo Bonzini
Cc: syzbot, akpm, davem, jhs, jiri, kvm, linux-fsdevel, linux-kernel,
mingo, mlevitsk, netdev, peterz, syzkaller-bugs, tglx,
vinicius.gomes, viro, xiyou.wangcong
On Tue, May 10, 2022, Paolo Bonzini wrote:
> On 5/10/22 15:45, Sean Christopherson wrote:
> > >
> > > KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
> > >
> > > bisection log:https://syzkaller.appspot.com/x/bisect.txt?x=16dc2e49f00000
> > > start commit: ea4424be1688 Merge tag 'mtd/fixes-for-5.17-rc8' of git://g..
> > > git tree: upstream
> > > kernel config:https://syzkaller.appspot.com/x/.config?x=442f8ac61e60a75e
> > > dashboard link:https://syzkaller.appspot.com/bug?extid=0c6da80218456f1edc36
> > > syz repro:https://syzkaller.appspot.com/x/repro.syz?x=1685af9e700000
> > > C reproducer:https://syzkaller.appspot.com/x/repro.c?x=11b09df1700000
> > >
> > > If the result looks correct, please mark the issue as fixed by replying with:
> > >
> > > #syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
> > >
> > > For information about bisection process see:https://goo.gl/tpsmEJ#bisection
> > #syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
> >
>
> Are you sure? The hang is in synchronize_*rcu* and the testcase is unrelated
> to KVM. It seems like the testcase is not 100% reproducible.
Ugh, syzbot seems to have bundled multiple unrelated errors together. The splat
that comes up first on the dashboard is definitely the KVM bug:
INFO: task syz-executor500:19706 blocked for more than 143 seconds.
Not tainted 5.17.0-rc7-syzkaller-00020-gea4424be1688 #0
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
task:syz-executor500 state:D stack:27048 pid:19706 ppid: 3644 flags:0x00000004
Call Trace:
<TASK>
context_switch kernel/sched/core.c:4995 [inline]
__schedule+0xa94/0x4910 kernel/sched/core.c:6304
schedule+0xd2/0x260 kernel/sched/core.c:6377
schedule_timeout+0x1db/0x2a0 kernel/time/timer.c:1857
do_wait_for_common kernel/sched/completion.c:85 [inline]
__wait_for_common+0x2af/0x360 kernel/sched/completion.c:106
__synchronize_srcu+0x1f2/0x290 kernel/rcu/srcutree.c:930
kvm_swap_active_memslots+0x410/0x800 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1473
kvm_activate_memslot arch/x86/kvm/../../../virt/kvm/kvm_main.c:1595 [inline]
kvm_create_memslot arch/x86/kvm/../../../virt/kvm/kvm_main.c:1660 [inline]
kvm_set_memslot+0xa67/0x1010 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1772
__kvm_set_memory_region+0xf02/0x11f0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:1914
kvm_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1927 [inline]
kvm_vm_ioctl_set_memory_region arch/x86/kvm/../../../virt/kvm/kvm_main.c:1939 [inline]
kvm_vm_ioctl+0x51a/0x22c0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4492
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
But there are multiple other errors that are indeed not the KVM bug.
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in synchronize_rcu (3)
2022-05-10 13:45 ` Sean Christopherson
@ 2022-05-10 13:50 ` Paolo Bonzini
2022-05-10 13:56 ` Sean Christopherson
0 siblings, 1 reply; 7+ messages in thread
From: Paolo Bonzini @ 2022-05-10 13:50 UTC (permalink / raw)
To: Sean Christopherson, syzbot
Cc: akpm, davem, jhs, jiri, kvm, linux-fsdevel, linux-kernel, mingo,
mlevitsk, netdev, peterz, syzkaller-bugs, tglx, vinicius.gomes,
viro, xiyou.wangcong
On 5/10/22 15:45, Sean Christopherson wrote:
>>
>> KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
>>
>> bisection log:https://syzkaller.appspot.com/x/bisect.txt?x=16dc2e49f00000
>> start commit: ea4424be1688 Merge tag 'mtd/fixes-for-5.17-rc8' of git://g..
>> git tree: upstream
>> kernel config:https://syzkaller.appspot.com/x/.config?x=442f8ac61e60a75e
>> dashboard link:https://syzkaller.appspot.com/bug?extid=0c6da80218456f1edc36
>> syz repro:https://syzkaller.appspot.com/x/repro.syz?x=1685af9e700000
>> C reproducer:https://syzkaller.appspot.com/x/repro.c?x=11b09df1700000
>>
>> If the result looks correct, please mark the issue as fixed by replying with:
>>
>> #syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
>>
>> For information about bisection process see:https://goo.gl/tpsmEJ#bisection
> #syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
>
Are you sure? The hang is in synchronize_*rcu* and the testcase is
unrelated to KVM. It seems like the testcase is not 100% reproducible.
Paolo
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in synchronize_rcu (3)
2022-05-10 8:51 ` [syzbot] " syzbot
@ 2022-05-10 13:45 ` Sean Christopherson
2022-05-10 13:50 ` Paolo Bonzini
0 siblings, 1 reply; 7+ messages in thread
From: Sean Christopherson @ 2022-05-10 13:45 UTC (permalink / raw)
To: syzbot
Cc: akpm, davem, jhs, jiri, kvm, linux-fsdevel, linux-kernel, mingo,
mlevitsk, netdev, pbonzini, peterz, syzkaller-bugs, tglx,
vinicius.gomes, viro, xiyou.wangcong
On Tue, May 10, 2022, syzbot wrote:
> syzbot suspects this issue was fixed by commit:
>
> commit 2d08935682ac5f6bfb70f7e6844ec27d4a245fa4
> Author: Sean Christopherson <seanjc@google.com>
> Date: Fri Apr 15 00:43:41 2022 +0000
>
> KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
>
> bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16dc2e49f00000
> start commit: ea4424be1688 Merge tag 'mtd/fixes-for-5.17-rc8' of git://g..
> git tree: upstream
> kernel config: https://syzkaller.appspot.com/x/.config?x=442f8ac61e60a75e
> dashboard link: https://syzkaller.appspot.com/bug?extid=0c6da80218456f1edc36
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1685af9e700000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11b09df1700000
>
> If the result looks correct, please mark the issue as fixed by replying with:
>
> #syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
>
> For information about bisection process see: https://goo.gl/tpsmEJ#bisection
#syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in synchronize_rcu (3)
[not found] <20220510115257.5804-1-hdanton@sina.com>
@ 2022-05-10 12:12 ` syzbot
0 siblings, 0 replies; 7+ messages in thread
From: syzbot @ 2022-05-10 12:12 UTC (permalink / raw)
To: hdanton, linux-kernel, syzkaller-bugs
Hello,
syzbot tried to test the proposed patch but the build/boot failed:
ackground, child pid 4958
[ 23.507564][ T4959] 8021q: adding VLAN 0 to HW filter on device bond0
[ 23.519205][ T4959] eql: remember to turn off Van-Jacobson compression on your slave devices
Starting sshd: OK
syzkaller
Warning: Permanently added '10.128.0.85' (ECDSA) to the list of known hosts.
2022/05/10 12:11:01 ignoring optional flag "raw_cover"="false"
2022/05/10 12:11:01 fuzzer started
2022/05/10 12:11:01 connecting to host at 10.128.0.169:33779
2022/05/10 12:11:01 checking machine...
2022/05/10 12:11:01 checking revisions...
2022/05/10 12:11:01 testing simple program...
syzkaller login: [ 40.935530][ T5379] cgroup: Unknown subsys name 'net'
[ 41.071569][ T5379] cgroup: Unknown subsys name 'rlimit'
[ 42.335602][ T5385] IPVS: ftp: loaded support on port[0] = 21
[ 42.394890][ T5385] chnl_net:caif_netlink_parms(): no params data found
[ 42.433361][ T5385] bridge0: port 1(bridge_slave_0) entered blocking state
[ 42.440978][ T5385] bridge0: port 1(bridge_slave_0) entered disabled state
[ 42.449123][ T5385] device bridge_slave_0 entered promiscuous mode
[ 42.458302][ T5385] bridge0: port 2(bridge_slave_1) entered blocking state
[ 42.466010][ T5385] bridge0: port 2(bridge_slave_1) entered disabled state
[ 42.473764][ T5385] device bridge_slave_1 entered promiscuous mode
[ 42.490493][ T5385] bond0: (slave bond_slave_0): Enslaving as an active interface with an up link
[ 42.502207][ T5385] bond0: (slave bond_slave_1): Enslaving as an active interface with an up link
[ 42.521537][ T5385] team0: Port device team_slave_0 added
[ 42.529481][ T5385] team0: Port device team_slave_1 added
[ 42.545295][ T5385] batman_adv: batadv0: Adding interface: batadv_slave_0
[ 42.552353][ T5385] batman_adv: batadv0: The MTU of interface batadv_slave_0 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
[ 42.578953][ T5385] batman_adv: batadv0: Not using interface batadv_slave_0 (retrying later): interface not active
[ 42.591532][ T5385] batman_adv: batadv0: Adding interface: batadv_slave_1
[ 42.598589][ T5385] batman_adv: batadv0: The MTU of interface batadv_slave_1 is too small (1500) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
[ 42.624881][ T5385] batman_adv: batadv0: Not using interface batadv_slave_1 (retrying later): interface not active
[ 42.647993][ T5385] device hsr_slave_0 entered promiscuous mode
[ 42.654646][ T5385] device hsr_slave_1 entered promiscuous mode
[ 42.722230][ T5385] netdevsim netdevsim0 netdevsim0: renamed from eth0
[ 42.732556][ T5385] netdevsim netdevsim0 netdevsim1: renamed from eth1
[ 42.742043][ T5385] netdevsim netdevsim0 netdevsim2: renamed from eth2
[ 42.750927][ T5385] netdevsim netdevsim0 netdevsim3: renamed from eth3
[ 42.771509][ T5385] bridge0: port 2(bridge_slave_1) entered blocking state
[ 42.779012][ T5385] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 42.786862][ T5385] bridge0: port 1(bridge_slave_0) entered blocking state
[ 42.794013][ T5385] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 42.833264][ T5385] 8021q: adding VLAN 0 to HW filter on device bond0
[ 42.845912][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
[ 42.854933][ T17] bridge0: port 1(bridge_slave_0) entered disabled state
[ 42.864247][ T17] bridge0: port 2(bridge_slave_1) entered disabled state
[ 42.872531][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready
[ 42.886684][ T5385] 8021q: adding VLAN 0 to HW filter on device team0
[ 42.897461][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_0: link becomes ready
[ 42.907316][ T17] bridge0: port 1(bridge_slave_0) entered blocking state
[ 42.914462][ T17] bridge0: port 1(bridge_slave_0) entered forwarding state
[ 42.937517][ T3022] IPv6: ADDRCONF(NETDEV_CHANGE): bridge_slave_1: link becomes ready
[ 42.947781][ T3022] bridge0: port 2(bridge_slave_1) entered blocking state
[ 42.954822][ T3022] bridge0: port 2(bridge_slave_1) entered forwarding state
[ 42.963063][ T3022] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_0: link becomes ready
[ 42.972691][ T3022] IPv6: ADDRCONF(NETDEV_CHANGE): team_slave_1: link becomes ready
[ 42.981899][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): team0: link becomes ready
[ 42.992884][ T2950] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_0: link becomes ready
[ 43.004741][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready
[ 43.016276][ T5385] IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready
[ 43.032499][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan0: link becomes ready
[ 43.040966][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): vxcan1: link becomes ready
[ 43.054589][ T5385] 8021q: adding VLAN 0 to HW filter on device batadv0
[ 43.072616][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_virt_wifi: link becomes ready
[ 43.090598][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_vlan: link becomes ready
[ 43.098877][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): vlan0: link becomes ready
[ 43.107021][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): vlan1: link becomes ready
[ 43.116925][ T5385] device veth0_vlan entered promiscuous mode
[ 43.128438][ T5385] device veth1_vlan entered promiscuous mode
[ 43.147614][ T3022] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan0: link becomes ready
[ 43.156727][ T3022] IPv6: ADDRCONF(NETDEV_CHANGE): macvlan1: link becomes ready
[ 43.166137][ T3022] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_macvtap: link becomes ready
[ 43.176463][ T5385] device veth0_macvtap entered promiscuous mode
[ 43.186693][ T5385] device veth1_macvtap entered promiscuous mode
[ 43.202698][ T5385] batman_adv: batadv0: Interface activated: batadv_slave_0
[ 43.210227][ T3022] IPv6: ADDRCONF(NETDEV_CHANGE): veth0_to_batadv: link becomes ready
[ 43.220664][ T3022] IPv6: ADDRCONF(NETDEV_CHANGE): macvtap0: link becomes ready
[ 43.232280][ T5385] batman_adv: batadv0: Interface activated: batadv_slave_1
[ 43.240456][ T5] IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready
[ 43.290329][ T1019] wlan0: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 43.304944][ T1019] wlan0: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 43.314460][ T8] wlan1: Created IBSS using preconfigured BSSID 50:50:50:50:50:50
[ 43.317814][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[ 43.322678][ T8] wlan1: Creating new IBSS network, BSSID 50:50:50:50:50:50
[ 43.340187][ T17] IPv6: ADDRCONF(NETDEV_CHANGE): wlan1: link becomes ready
[ 43.375727][ T5385] cgroup: cgroup: disabling cgroup2 socket matching due to net_prio or net_cls activation
2022/05/10 12:11:04 building call list...
executing program
[ 43.949689][ T5385] ==================================================================
[ 43.958088][ T5385] BUG: KASAN: use-after-free in task_active_pid_ns+0xb1/0xd0
[ 43.965539][ T5385] Read of size 4 at addr ffff88823b705004 by task syz-executor.0/5385
[ 43.973758][ T5385]
[ 43.976084][ T5385] CPU: 1 PID: 5385 Comm: syz-executor.0 Not tainted 5.8.0-rc6-syzkaller-00003-g4fa640dc5230-dirty #0
[ 43.987108][ T5385] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 43.997146][ T5385] Call Trace:
[ 44.000503][ T5385] dump_stack+0xf6/0x16e
[ 44.004912][ T5385] ? task_active_pid_ns+0xb1/0xd0
[ 44.009937][ T5385] ? task_active_pid_ns+0xb1/0xd0
[ 44.014952][ T5385] print_address_description.constprop.0.cold+0xae/0x467
[ 44.022061][ T5385] ? __wake_up_common_lock+0xde/0x130
[ 44.027426][ T5385] ? vprintk_func+0x95/0x241
[ 44.032153][ T5385] ? task_active_pid_ns+0xb1/0xd0
[ 44.037652][ T5385] kasan_report.cold+0x1f/0x37
[ 44.042526][ T5385] ? task_active_pid_ns+0xb1/0xd0
[ 44.049012][ T5385] task_active_pid_ns+0xb1/0xd0
[ 44.053869][ T5385] do_notify_parent+0x33a/0xf80
[ 44.058742][ T5385] ? do_exit+0x24f2/0x2ce0
[ 44.063163][ T5385] ? send_sigqueue+0x810/0x810
[ 44.068821][ T5385] ? lock_release+0x810/0x810
[ 44.073605][ T5385] ? zap_pid_ns_processes+0x547/0x6b0
[ 44.079083][ T5385] ? lockdep_hardirqs_on_prepare+0x383/0x560
[ 44.085067][ T5385] do_exit+0x222c/0x2ce0
[ 44.089312][ T5385] ? find_held_lock+0x2d/0x110
[ 44.094251][ T5385] ? mm_update_next_owner+0x7b0/0x7b0
[ 44.099762][ T5385] ? get_signal+0x330/0x20c0
[ 44.104390][ T5385] ? lock_downgrade+0x730/0x730
[ 44.109354][ T5385] do_group_exit+0x125/0x310
[ 44.113999][ T5385] get_signal+0x408/0x20c0
[ 44.118435][ T5385] ? __sanitizer_cov_trace_switch+0x45/0x70
[ 44.124335][ T5385] do_signal+0x82/0x2490
[ 44.128581][ T5385] ? preempt_schedule_irq+0x54/0xe0
[ 44.133868][ T5385] ? loop_configure+0x1350/0x1350
[ 44.138899][ T5385] ? copy_siginfo_to_user32+0xa0/0xa0
[ 44.144267][ T5385] ? lockdep_hardirqs_on_prepare+0x383/0x560
[ 44.150252][ T5385] ? blkdev_common_ioctl+0x1760/0x1760
[ 44.155730][ T5385] ? __prepare_exit_to_usermode+0x105/0x1e0
[ 44.161630][ T5385] ? lockdep_hardirqs_on_prepare+0x383/0x560
[ 44.167607][ T5385] __prepare_exit_to_usermode+0x12f/0x1e0
[ 44.173842][ T5385] do_syscall_64+0x52/0xe0
[ 44.178260][ T5385] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 44.184141][ T5385] RIP: 0033:0x7fc9dc7e3e07
[ 44.188537][ T5385] Code: Bad RIP value.
[ 44.192952][ T5385] RSP: 002b:00007fc9dce2ad78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 44.201527][ T5385] RAX: fffffffffffffffa RBX: 00007fc9dce2ae00 RCX: 00007fc9dc7e3e07
[ 44.209505][ T5385] RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003
[ 44.217473][ T5385] RBP: 0000000000000003 R08: 0000000000000000 R09: 00007fc9dce2ac10
[ 44.225715][ T5385] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000032
[ 44.233866][ T5385] R13: 000000000000a98e R14: 0000000000000003 R15: 00007fc9dce2ae40
[ 44.241969][ T5385]
[ 44.244321][ T5385] Allocated by task 0:
[ 44.248405][ T5385] save_stack+0x1b/0x40
[ 44.253199][ T5385] __kasan_kmalloc.constprop.0+0xc2/0xd0
[ 44.258892][ T5385] kmem_cache_alloc+0xd7/0x310
[ 44.263743][ T5385] alloc_pid+0xd5/0xda0
[ 44.267914][ T5385] copy_process+0x3194/0x6f00
[ 44.272589][ T5385] _do_fork+0x12c/0xa90
[ 44.276747][ T5385] kernel_thread+0xb5/0xf0
[ 44.281155][ T5385] rest_init+0x23/0x460
[ 44.285492][ T5385] start_kernel+0x9a7/0x9e2
[ 44.290003][ T5385] secondary_startup_64+0xa4/0xb0
[ 44.295023][ T5385]
[ 44.297432][ T5385] Freed by task 5379:
[ 44.301413][ T5385] save_stack+0x1b/0x40
[ 44.305562][ T5385] __kasan_slab_free+0x11f/0x160
[ 44.310492][ T5385] slab_free_freelist_hook+0x53/0x140
[ 44.315869][ T5385] kmem_cache_free+0x8a/0x380
[ 44.320637][ T5385] put_pid.part.0+0xfa/0x150
[ 44.325216][ T5385] put_pid+0x1b/0x30
[ 44.329280][ T5385] proc_do_cad_pid+0x153/0x180
[ 44.334036][ T5385] proc_sys_call_handler+0x28f/0x5b0
[ 44.339320][ T5385] vfs_write+0x2b0/0x6b0
[ 44.343560][ T5385] ksys_write+0x12d/0x250
[ 44.347892][ T5385] do_syscall_64+0x46/0xe0
[ 44.352313][ T5385] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 44.358195][ T5385]
[ 44.360517][ T5385] The buggy address belongs to the object at ffff88823b705000
[ 44.360517][ T5385] which belongs to the cache pid of size 224
[ 44.373875][ T5385] The buggy address is located 4 bytes inside of
[ 44.373875][ T5385] 224-byte region [ffff88823b705000, ffff88823b7050e0)
[ 44.386972][ T5385] The buggy address belongs to the page:
[ 44.392605][ T5385] page:ffffea0008edc140 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0
[ 44.401714][ T5385] flags: 0x57ff00000000200(slab)
[ 44.406664][ T5385] raw: 057ff00000000200 dead000000000100 dead000000000122 ffff8880b5889400
[ 44.415255][ T5385] raw: 0000000000000000 00000000000c000c 00000001ffffffff 0000000000000000
[ 44.423841][ T5385] page dumped because: kasan: bad access detected
[ 44.430383][ T5385] page_owner tracks the page as allocated
[ 44.436115][ T5385] page last allocated via order 0, migratetype Unmovable, gfp_mask 0x0()
[ 44.444534][ T5385] register_early_stack+0x66/0xb0
[ 44.449557][ T5385] init_page_owner+0x6b/0x7e0
[ 44.454230][ T5385] page_ext_init+0x3a8/0x3b8
[ 44.458814][ T5385] kernel_init_freeable+0x31a/0x691
[ 44.463993][ T5385] page_owner free stack trace missing
[ 44.469360][ T5385]
[ 44.471943][ T5385] Memory state around the buggy address:
[ 44.477750][ T5385] ffff88823b704f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[ 44.485827][ T5385] ffff88823b704f80: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
[ 44.494006][ T5385] >ffff88823b705000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 44.502327][ T5385] ^
[ 44.506747][ T5385] ffff88823b705080: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
[ 44.514917][ T5385] ffff88823b705100: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
[ 44.523036][ T5385] ==================================================================
[ 44.531112][ T5385] Disabling lock debugging due to kernel taint
[ 44.537345][ T5385] Kernel panic - not syncing: panic_on_warn set ...
[ 44.543927][ T5385] CPU: 1 PID: 5385 Comm: syz-executor.0 Tainted: G B 5.8.0-rc6-syzkaller-00003-g4fa640dc5230-dirty #0
[ 44.556232][ T5385] Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 44.566311][ T5385] Call Trace:
[ 44.569690][ T5385] dump_stack+0xf6/0x16e
[ 44.573924][ T5385] panic+0x370/0x7b0
[ 44.577811][ T5385] ? __warn_printk+0xf3/0xf3
[ 44.582893][ T5385] ? _raw_spin_unlock_irqrestore+0x2a/0x60
[ 44.588693][ T5385] ? task_active_pid_ns+0xb1/0xd0
[ 44.593702][ T5385] ? task_active_pid_ns+0xb1/0xd0
[ 44.598801][ T5385] end_report+0x4d/0x53
[ 44.603132][ T5385] kasan_report.cold+0xd/0x37
[ 44.607988][ T5385] ? task_active_pid_ns+0xb1/0xd0
[ 44.613020][ T5385] task_active_pid_ns+0xb1/0xd0
[ 44.617896][ T5385] do_notify_parent+0x33a/0xf80
[ 44.622770][ T5385] ? do_exit+0x24f2/0x2ce0
[ 44.627188][ T5385] ? send_sigqueue+0x810/0x810
[ 44.632657][ T5385] ? lock_release+0x810/0x810
[ 44.637341][ T5385] ? zap_pid_ns_processes+0x547/0x6b0
[ 44.642962][ T5385] ? lockdep_hardirqs_on_prepare+0x383/0x560
[ 44.649038][ T5385] do_exit+0x222c/0x2ce0
[ 44.653378][ T5385] ? find_held_lock+0x2d/0x110
[ 44.658402][ T5385] ? mm_update_next_owner+0x7b0/0x7b0
[ 44.663759][ T5385] ? get_signal+0x330/0x20c0
[ 44.668437][ T5385] ? lock_downgrade+0x730/0x730
[ 44.673317][ T5385] do_group_exit+0x125/0x310
[ 44.677990][ T5385] get_signal+0x408/0x20c0
[ 44.682633][ T5385] ? __sanitizer_cov_trace_switch+0x45/0x70
[ 44.688780][ T5385] do_signal+0x82/0x2490
[ 44.693465][ T5385] ? preempt_schedule_irq+0x54/0xe0
[ 44.698679][ T5385] ? loop_configure+0x1350/0x1350
[ 44.703960][ T5385] ? copy_siginfo_to_user32+0xa0/0xa0
[ 44.712100][ T5385] ? lockdep_hardirqs_on_prepare+0x383/0x560
[ 44.718153][ T5385] ? blkdev_common_ioctl+0x1760/0x1760
[ 44.723592][ T5385] ? __prepare_exit_to_usermode+0x105/0x1e0
[ 44.729636][ T5385] ? lockdep_hardirqs_on_prepare+0x383/0x560
[ 44.735596][ T5385] __prepare_exit_to_usermode+0x12f/0x1e0
[ 44.741652][ T5385] do_syscall_64+0x52/0xe0
[ 44.746053][ T5385] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[ 44.751954][ T5385] RIP: 0033:0x7fc9dc7e3e07
[ 44.756428][ T5385] Code: Bad RIP value.
[ 44.760473][ T5385] RSP: 002b:00007fc9dce2ad78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[ 44.769542][ T5385] RAX: fffffffffffffffa RBX: 00007fc9dce2ae00 RCX: 00007fc9dc7e3e07
[ 44.779439][ T5385] RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003
[ 44.787651][ T5385] RBP: 0000000000000003 R08: 0000000000000000 R09: 00007fc9dce2ac10
[ 44.795603][ T5385] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000032
[ 44.803567][ T5385] R13: 000000000000a98e R14: 0000000000000003 R15: 00007fc9dce2ae40
[ 44.812073][ T5385] Kernel Offset: disabled
[ 44.816388][ T5385] Rebooting in 86400 seconds..
Error text is too large and was truncated, full error text is at:
https://syzkaller.appspot.com/x/error.txt?x=159d83faf00000
Tested on:
commit: 4fa640dc Merge tag 'vfio-v5.8-rc7' of git://github.com..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
kernel config: https://syzkaller.appspot.com/x/.config?x=c8387e9c623864db
dashboard link: https://syzkaller.appspot.com/bug?extid=0c6da80218456f1edc36
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch: https://syzkaller.appspot.com/x/patch.diff?x=12a4f831f00000
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in synchronize_rcu (3)
[not found] <20220510110816.5751-1-hdanton@sina.com>
@ 2022-05-10 11:43 ` syzbot
0 siblings, 0 replies; 7+ messages in thread
From: syzbot @ 2022-05-10 11:43 UTC (permalink / raw)
To: hdanton, linux-kernel, syzkaller-bugs
Hello,
syzbot tried to test the proposed patch but the build/boot failed:
net/sched/sch_taprio.c:750:54: error: expected ')' before 'hrtimer_set_expires'
net/sched/sch_taprio.c:760:1: error: expected expression before '}' token
Tested on:
commit: 4fa640dc Merge tag 'vfio-v5.8-rc7' of git://github.com..
git tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
dashboard link: https://syzkaller.appspot.com/bug?extid=0c6da80218456f1edc36
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
patch: https://syzkaller.appspot.com/x/patch.diff?x=155bd6b9f00000
^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [syzbot] INFO: task hung in synchronize_rcu (3)
2020-07-22 18:22 syzbot
@ 2022-05-10 8:51 ` syzbot
2022-05-10 13:45 ` Sean Christopherson
0 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2022-05-10 8:51 UTC (permalink / raw)
To: akpm, davem, jhs, jiri, kvm, linux-fsdevel, linux-kernel, mingo,
mlevitsk, netdev, pbonzini, peterz, seanjc, syzkaller-bugs, tglx,
vinicius.gomes, viro, xiyou.wangcong
syzbot suspects this issue was fixed by commit:
commit 2d08935682ac5f6bfb70f7e6844ec27d4a245fa4
Author: Sean Christopherson <seanjc@google.com>
Date: Fri Apr 15 00:43:41 2022 +0000
KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=16dc2e49f00000
start commit: ea4424be1688 Merge tag 'mtd/fixes-for-5.17-rc8' of git://g..
git tree: upstream
kernel config: https://syzkaller.appspot.com/x/.config?x=442f8ac61e60a75e
dashboard link: https://syzkaller.appspot.com/bug?extid=0c6da80218456f1edc36
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1685af9e700000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=11b09df1700000
If the result looks correct, please mark the issue as fixed by replying with:
#syz fix: KVM: x86: Don't re-acquire SRCU lock in complete_emulated_io()
For information about bisection process see: https://goo.gl/tpsmEJ#bisection
^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2022-05-11 13:44 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
[not found] <20220511132050.5868-1-hdanton@sina.com>
2022-05-11 13:44 ` [syzbot] INFO: task hung in synchronize_rcu (3) syzbot
[not found] <20220510115257.5804-1-hdanton@sina.com>
2022-05-10 12:12 ` syzbot
[not found] <20220510110816.5751-1-hdanton@sina.com>
2022-05-10 11:43 ` syzbot
2020-07-22 18:22 syzbot
2022-05-10 8:51 ` [syzbot] " syzbot
2022-05-10 13:45 ` Sean Christopherson
2022-05-10 13:50 ` Paolo Bonzini
2022-05-10 13:56 ` Sean Christopherson
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