Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On Wed, 20 Dec 2017, at 3:14 PM, Tejun Heo wrote:
> On Tue, Dec 19, 2017 at 05:42:39AM -0800, Tejun Heo wrote:
> > On Sun, Dec 17, 2017 at 03:24:48PM -0800, vcap...@pengaru.com wrote:
> > > On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
> > > > I just upgraded to 4.14.7 and tried to reproduce this error, this time
> > > > under strace. As you can see this happens when systemctl tries to read
> > > > a specific entry under /sys/fs . In case this matters, the entry is for
> > > > a small virtual machine running under qemu/kvm and managed by libvirt.
> > > >
> > > > open("/sys/fs/cgroup/unified/machine.slice",
> > > > O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> > > > fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> > > > getdents(5, /* 12 entries */, 32768)= 464
> > > > openat(AT_FDCWD,
> > > > "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> > > > O_RDONLY|O_CLOEXEC) = 8
> > > > fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> > > > read(8, ) = ?
> > > > +++ killed by SIGKILL +++
> > > > [1]12078 killed strace -- systemctl status
> > > >
> > > >
> > >
> > > This recently came through lkml, may be related:
> > > https://marc.info/?l=linux-kernel=151320108922415=2
> >
> > It looks like it could be the same problem. Working on the fix now.
> > Will let you know when I have something.
>
> Fix posted.
>
> http://lkml.kernel.org/r/20171220151331.ga3413...@devbig577.frc2.facebook.com
>
Thank you Tejun - I tested this fix and it works for me
B.
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On Wed, 20 Dec 2017, at 3:14 PM, Tejun Heo wrote:
> On Tue, Dec 19, 2017 at 05:42:39AM -0800, Tejun Heo wrote:
> > On Sun, Dec 17, 2017 at 03:24:48PM -0800, vcap...@pengaru.com wrote:
> > > On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
> > > > I just upgraded to 4.14.7 and tried to reproduce this error, this time
> > > > under strace. As you can see this happens when systemctl tries to read
> > > > a specific entry under /sys/fs . In case this matters, the entry is for
> > > > a small virtual machine running under qemu/kvm and managed by libvirt.
> > > >
> > > > open("/sys/fs/cgroup/unified/machine.slice",
> > > > O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> > > > fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> > > > getdents(5, /* 12 entries */, 32768)= 464
> > > > openat(AT_FDCWD,
> > > > "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> > > > O_RDONLY|O_CLOEXEC) = 8
> > > > fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> > > > read(8, ) = ?
> > > > +++ killed by SIGKILL +++
> > > > [1]12078 killed strace -- systemctl status
> > > >
> > > >
> > >
> > > This recently came through lkml, may be related:
> > > https://marc.info/?l=linux-kernel=151320108922415=2
> >
> > It looks like it could be the same problem. Working on the fix now.
> > Will let you know when I have something.
>
> Fix posted.
>
> http://lkml.kernel.org/r/20171220151331.ga3413...@devbig577.frc2.facebook.com
>
Thank you Tejun - I tested this fix and it works for me
B.
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On Tue, Dec 19, 2017 at 05:42:39AM -0800, Tejun Heo wrote:
> On Sun, Dec 17, 2017 at 03:24:48PM -0800, vcap...@pengaru.com wrote:
> > On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
> > > I just upgraded to 4.14.7 and tried to reproduce this error, this time
> > > under strace. As you can see this happens when systemctl tries to read a
> > > specific entry under /sys/fs . In case this matters, the entry is for a
> > > small virtual machine running under qemu/kvm and managed by libvirt.
> > >
> > > open("/sys/fs/cgroup/unified/machine.slice",
> > > O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> > > fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> > > getdents(5, /* 12 entries */, 32768)= 464
> > > openat(AT_FDCWD,
> > > "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> > > O_RDONLY|O_CLOEXEC) = 8
> > > fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> > > read(8, ) = ?
> > > +++ killed by SIGKILL +++
> > > [1]12078 killed strace -- systemctl status
> > >
> > >
> >
> > This recently came through lkml, may be related:
> > https://marc.info/?l=linux-kernel=151320108922415=2
>
> It looks like it could be the same problem. Working on the fix now.
> Will let you know when I have something.
Fix posted.
http://lkml.kernel.org/r/20171220151331.ga3413...@devbig577.frc2.facebook.com
Thanks.
--
tejun
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On Tue, Dec 19, 2017 at 05:42:39AM -0800, Tejun Heo wrote:
> On Sun, Dec 17, 2017 at 03:24:48PM -0800, vcap...@pengaru.com wrote:
> > On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
> > > I just upgraded to 4.14.7 and tried to reproduce this error, this time
> > > under strace. As you can see this happens when systemctl tries to read a
> > > specific entry under /sys/fs . In case this matters, the entry is for a
> > > small virtual machine running under qemu/kvm and managed by libvirt.
> > >
> > > open("/sys/fs/cgroup/unified/machine.slice",
> > > O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> > > fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> > > getdents(5, /* 12 entries */, 32768)= 464
> > > openat(AT_FDCWD,
> > > "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> > > O_RDONLY|O_CLOEXEC) = 8
> > > fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> > > read(8, ) = ?
> > > +++ killed by SIGKILL +++
> > > [1]12078 killed strace -- systemctl status
> > >
> > >
> >
> > This recently came through lkml, may be related:
> > https://marc.info/?l=linux-kernel=151320108922415=2
>
> It looks like it could be the same problem. Working on the fix now.
> Will let you know when I have something.
Fix posted.
http://lkml.kernel.org/r/20171220151331.ga3413...@devbig577.frc2.facebook.com
Thanks.
--
tejun
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
Hello, On Mon, Dec 18, 2017 at 03:17:54PM -0500, George Amanakis wrote: > I can replicate this on a Thinkpad X230i running archlinux with latest > 4.14.7 kernel, without the ZFS modules. > > Steps to reproduce: > 1) create a virtual machine using libvirt (attached xml) > 2) virsh start vm > 3) head /sys/fs/cgroup/unified/machine.slice/machine- > qemu\\x2d2\\x2dvm.scope/cgroup.procs It took some massaging but I can reproduce the problem. Will report when I know more. Thanks. -- tejun
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
Hello, On Mon, Dec 18, 2017 at 03:17:54PM -0500, George Amanakis wrote: > I can replicate this on a Thinkpad X230i running archlinux with latest > 4.14.7 kernel, without the ZFS modules. > > Steps to reproduce: > 1) create a virtual machine using libvirt (attached xml) > 2) virsh start vm > 3) head /sys/fs/cgroup/unified/machine.slice/machine- > qemu\\x2d2\\x2dvm.scope/cgroup.procs It took some massaging but I can reproduce the problem. Will report when I know more. Thanks. -- tejun
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On Sun, Dec 17, 2017 at 03:24:48PM -0800, vcap...@pengaru.com wrote:
> On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
> > I just upgraded to 4.14.7 and tried to reproduce this error, this time
> > under strace. As you can see this happens when systemctl tries to read a
> > specific entry under /sys/fs . In case this matters, the entry is for a
> > small virtual machine running under qemu/kvm and managed by libvirt.
> >
> > open("/sys/fs/cgroup/unified/machine.slice",
> > O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> > fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> > getdents(5, /* 12 entries */, 32768)= 464
> > openat(AT_FDCWD,
> > "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> > O_RDONLY|O_CLOEXEC) = 8
> > fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> > read(8, ) = ?
> > +++ killed by SIGKILL +++
> > [1]12078 killed strace -- systemctl status
> >
> >
>
> This recently came through lkml, may be related:
> https://marc.info/?l=linux-kernel=151320108922415=2
It looks like it could be the same problem. Working on the fix now.
Will let you know when I have something.
Thanks.
--
tejun
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On Sun, Dec 17, 2017 at 03:24:48PM -0800, vcap...@pengaru.com wrote:
> On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
> > I just upgraded to 4.14.7 and tried to reproduce this error, this time
> > under strace. As you can see this happens when systemctl tries to read a
> > specific entry under /sys/fs . In case this matters, the entry is for a
> > small virtual machine running under qemu/kvm and managed by libvirt.
> >
> > open("/sys/fs/cgroup/unified/machine.slice",
> > O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> > fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> > getdents(5, /* 12 entries */, 32768)= 464
> > openat(AT_FDCWD,
> > "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> > O_RDONLY|O_CLOEXEC) = 8
> > fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> > read(8, ) = ?
> > +++ killed by SIGKILL +++
> > [1]12078 killed strace -- systemctl status
> >
> >
>
> This recently came through lkml, may be related:
> https://marc.info/?l=linux-kernel=151320108922415=2
It looks like it could be the same problem. Working on the fix now.
Will let you know when I have something.
Thanks.
--
tejun
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
I can replicate this on a Thinkpad X230i running archlinux with latest 4.14.7 kernel, without the ZFS modules. Steps to reproduce: 1) create a virtual machine using libvirt (attached xml) 2) virsh start vm 3) head /sys/fs/cgroup/unified/machine.slice/machine- qemu\\x2d2\\x2dvm.scope/cgroup.procs This hangs the laptop requiring a hard reset. Regards, George vm.xml Description: XML document
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
I can replicate this on a Thinkpad X230i running archlinux with latest 4.14.7 kernel, without the ZFS modules. Steps to reproduce: 1) create a virtual machine using libvirt (attached xml) 2) virsh start vm 3) head /sys/fs/cgroup/unified/machine.slice/machine- qemu\\x2d2\\x2dvm.scope/cgroup.procs This hangs the laptop requiring a hard reset. Regards, George vm.xml Description: XML document
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On 17/12/2017 23:24, vcap...@pengaru.com wrote:
On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
I just upgraded to 4.14.7 and tried to reproduce this error, this time under
strace. As you can see this happens when systemctl tries to read a specific
entry under /sys/fs . In case this matters, the entry is for a small virtual
machine running under qemu/kvm and managed by libvirt.
open("/sys/fs/cgroup/unified/machine.slice",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
getdents(5, /* 12 entries */, 32768)= 464
openat(AT_FDCWD,
"/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
O_RDONLY|O_CLOEXEC) = 8
fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
read(8, ) = ?
+++ killed by SIGKILL +++
[1]12078 killed strace -- systemctl status
This recently came through lkml, may be related:
https://marc.info/?l=linux-kernel=151320108922415=2
thank you, it certainly seems related. Is there some debugging option I could
enable, or patch I could apply, which would make the point of data corruption
easier to find? I'm ok taking untested patches, if that helps finding the
location of the bug.
B.
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On 17/12/2017 23:24, vcap...@pengaru.com wrote:
On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
I just upgraded to 4.14.7 and tried to reproduce this error, this time under
strace. As you can see this happens when systemctl tries to read a specific
entry under /sys/fs . In case this matters, the entry is for a small virtual
machine running under qemu/kvm and managed by libvirt.
open("/sys/fs/cgroup/unified/machine.slice",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
getdents(5, /* 12 entries */, 32768)= 464
openat(AT_FDCWD,
"/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
O_RDONLY|O_CLOEXEC) = 8
fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
read(8, ) = ?
+++ killed by SIGKILL +++
[1]12078 killed strace -- systemctl status
This recently came through lkml, may be related:
https://marc.info/?l=linux-kernel=151320108922415=2
thank you, it certainly seems related. Is there some debugging option I could
enable, or patch I could apply, which would make the point of data corruption
easier to find? I'm ok taking untested patches, if that helps finding the
location of the bug.
B.
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
> I just upgraded to 4.14.7 and tried to reproduce this error, this time under
> strace. As you can see this happens when systemctl tries to read a specific
> entry under /sys/fs . In case this matters, the entry is for a small virtual
> machine running under qemu/kvm and managed by libvirt.
>
> open("/sys/fs/cgroup/unified/machine.slice",
> O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> getdents(5, /* 12 entries */, 32768)= 464
> openat(AT_FDCWD,
> "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> O_RDONLY|O_CLOEXEC) = 8
> fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> read(8, ) = ?
> +++ killed by SIGKILL +++
> [1]12078 killed strace -- systemctl status
>
>
This recently came through lkml, may be related:
https://marc.info/?l=linux-kernel=151320108922415=2
CCd Tejun
> B.
>
>
> [ 1889.226051]
>
> [ 1889.235286] UBSAN: Undefined behaviour in kernel/cgroup/pids.c:67:9
> [ 1889.241563] member access within null pointer of type 'struct pids_cgroup'
> [ 1889.249920]
>
> [ 1889.259698] BUG: unable to handle kernel NULL pointer dereference at
> 00b0
> [ 1889.267524] IP: pids_free+0x28/0xb0
> [ 1889.272394] PGD 0 P4D 0
> [ 1889.274925] Oops: [#1] SMP
> [ 1889.278061] Modules linked in: ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter devlink joydev hid_logitech_hidpp mxm_wmi
> intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel
> kvm crct10dif_pclmul crc32_pclmu
> l crc32c_intel ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd
> glue_helper cryptd ext4 intel_cstate crc16 mbcache jbd2 fscrypto
> nls_iso8859_1 nls_cp437 evdev input_leds led_class vfat fat intel_rapl_perf
> mac_hid pcspkr hid_logitech_dj igb ptp mei_me pps_
> core i2c_i801 i2c_algo_bit mei lpc_ich ioatdma tpm_tis tpm_tis_core dca
> shpchp tpm wmi button sch_fq_codel sg ip_tables x_tables usbhid hid zfs(PO)
> zunicode(PO) zavl(PO) icp(PO) sd_mod serio_raw atkbd libps2 isci ahci libsas
> libahci xhci_pci ehci_pci mpt3sas xhci_hc
> d ehci_hcd raid_class libata
> [ 1889.349864] scsi_transport_sas usbcore scsi_mod usb_common i8042 serio
> zcommon(PO) znvpair(PO) spl(O) nvme nvme_core bridge stp llc vhost_net tun
> tap vhost vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio
> [ 1889.368439] CPU: 1 PID: 12084 Comm: systemctl Tainted: PW O
> 4.14.7-1-ARCH #1
> [ 1889.376525] Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014
> [ 1889.383474] task: 93149aaec140 task.stack: a88c3836c000
> [ 1889.389387] RIP: 0010:pids_free+0x28/0xb0
> [ 1889.393388] RSP: 0018:a88c3836fcc8 EFLAGS: 00010282
> [ 1889.398605] RAX: RBX: RCX:
> 0006
> [ 1889.405731] RDX: RSI: 0202 RDI:
> 0202
> [ 1889.412854] RBP: 931499ab2d58 R08: 079a R09:
>
> [ 1889.419979] R10: 001f5954 R11: 0003d040 R12:
> 56e21a48
> [ 1889.427102] R13: a91de5c0 R14: 93247b0598c0 R15:
> a91cd0a0
> [ 1889.434227] FS: 7f18eee6b8c0() GS:931ebfa4()
> knlGS:
> [ 1889.442302] CS: 0010 DS: ES: CR0: 80050033
> [ 1889.448041] CR2: 00b0 CR3: 000611019003 CR4:
> 001626e0
> [ 1889.455164] Call Trace:
> [ 1889.457610] cgroup_free+0xaa/0x190
> [ 1889.461095] __put_task_struct+0x68/0x230
> [ 1889.465105] ? seq_printf+0x4e/0x70
> [ 1889.468591] css_task_iter_next+0x74/0x90
> [ 1889.472594] kernfs_seq_next+0x58/0x110
> [ 1889.476424] seq_read+0x36c/0x620
> [ 1889.479735] __vfs_read+0x54/0x2e0
> [ 1889.483134] vfs_read+0x9d/0x200
> [ 1889.486358] SyS_read+0x52/0xc0
> [ 1889.489494] do_syscall_64+0x69/0x1e0
> [ 1889.493152] entry_SYSCALL64_slow_path+0x25/0x25
> [ 1889.497771] RIP: 0033:0x7f18ee784a11
> [ 1889.501341] RSP: 002b:7ffd56942618 EFLAGS: 0246 ORIG_RAX:
>
> [ 1889.508897] RAX: ffda RBX: 559a9ae6d260 RCX:
> 7f18ee784a11
> [ 1889.516022] RDX: 1000 RSI: 559a9ae80f70 RDI:
> 0008
> [ 1889.523145] RBP: 0d68 R08: 0003 R09:
> ffb0
> [ 1889.530270] R10: 1000 R11: 0246 R12:
> 7f18eea4b700
> [ 1889.537395] R13: 7f18eea4c240 R14: 559a9ae6d260 R15:
>
> [ 1889.544518] Code: 44 00 00 0f 1f 44 00 00 48 81 ff c8 f7 ff ff 55 53 48 89
> fb 74 4c 48 8b 9b 38 08 00 00 48 85 db 74 7c 48 8b 5b 50 48 85 db 74 63 <48>
> 83 bb b0 00 00 00 00 74 2a 48 c7 c5 60 2e 1e a9 48 89 df e8
> [ 1889.563368] RIP:
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On Sun, Dec 17, 2017 at 05:49:44PM +, Bronek Kozicki wrote:
> I just upgraded to 4.14.7 and tried to reproduce this error, this time under
> strace. As you can see this happens when systemctl tries to read a specific
> entry under /sys/fs . In case this matters, the entry is for a small virtual
> machine running under qemu/kvm and managed by libvirt.
>
> open("/sys/fs/cgroup/unified/machine.slice",
> O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> getdents(5, /* 12 entries */, 32768)= 464
> openat(AT_FDCWD,
> "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> O_RDONLY|O_CLOEXEC) = 8
> fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> read(8, ) = ?
> +++ killed by SIGKILL +++
> [1]12078 killed strace -- systemctl status
>
>
This recently came through lkml, may be related:
https://marc.info/?l=linux-kernel=151320108922415=2
CCd Tejun
> B.
>
>
> [ 1889.226051]
>
> [ 1889.235286] UBSAN: Undefined behaviour in kernel/cgroup/pids.c:67:9
> [ 1889.241563] member access within null pointer of type 'struct pids_cgroup'
> [ 1889.249920]
>
> [ 1889.259698] BUG: unable to handle kernel NULL pointer dereference at
> 00b0
> [ 1889.267524] IP: pids_free+0x28/0xb0
> [ 1889.272394] PGD 0 P4D 0
> [ 1889.274925] Oops: [#1] SMP
> [ 1889.278061] Modules linked in: ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter devlink joydev hid_logitech_hidpp mxm_wmi
> intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel
> kvm crct10dif_pclmul crc32_pclmu
> l crc32c_intel ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd
> glue_helper cryptd ext4 intel_cstate crc16 mbcache jbd2 fscrypto
> nls_iso8859_1 nls_cp437 evdev input_leds led_class vfat fat intel_rapl_perf
> mac_hid pcspkr hid_logitech_dj igb ptp mei_me pps_
> core i2c_i801 i2c_algo_bit mei lpc_ich ioatdma tpm_tis tpm_tis_core dca
> shpchp tpm wmi button sch_fq_codel sg ip_tables x_tables usbhid hid zfs(PO)
> zunicode(PO) zavl(PO) icp(PO) sd_mod serio_raw atkbd libps2 isci ahci libsas
> libahci xhci_pci ehci_pci mpt3sas xhci_hc
> d ehci_hcd raid_class libata
> [ 1889.349864] scsi_transport_sas usbcore scsi_mod usb_common i8042 serio
> zcommon(PO) znvpair(PO) spl(O) nvme nvme_core bridge stp llc vhost_net tun
> tap vhost vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio
> [ 1889.368439] CPU: 1 PID: 12084 Comm: systemctl Tainted: PW O
> 4.14.7-1-ARCH #1
> [ 1889.376525] Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014
> [ 1889.383474] task: 93149aaec140 task.stack: a88c3836c000
> [ 1889.389387] RIP: 0010:pids_free+0x28/0xb0
> [ 1889.393388] RSP: 0018:a88c3836fcc8 EFLAGS: 00010282
> [ 1889.398605] RAX: RBX: RCX:
> 0006
> [ 1889.405731] RDX: RSI: 0202 RDI:
> 0202
> [ 1889.412854] RBP: 931499ab2d58 R08: 079a R09:
>
> [ 1889.419979] R10: 001f5954 R11: 0003d040 R12:
> 56e21a48
> [ 1889.427102] R13: a91de5c0 R14: 93247b0598c0 R15:
> a91cd0a0
> [ 1889.434227] FS: 7f18eee6b8c0() GS:931ebfa4()
> knlGS:
> [ 1889.442302] CS: 0010 DS: ES: CR0: 80050033
> [ 1889.448041] CR2: 00b0 CR3: 000611019003 CR4:
> 001626e0
> [ 1889.455164] Call Trace:
> [ 1889.457610] cgroup_free+0xaa/0x190
> [ 1889.461095] __put_task_struct+0x68/0x230
> [ 1889.465105] ? seq_printf+0x4e/0x70
> [ 1889.468591] css_task_iter_next+0x74/0x90
> [ 1889.472594] kernfs_seq_next+0x58/0x110
> [ 1889.476424] seq_read+0x36c/0x620
> [ 1889.479735] __vfs_read+0x54/0x2e0
> [ 1889.483134] vfs_read+0x9d/0x200
> [ 1889.486358] SyS_read+0x52/0xc0
> [ 1889.489494] do_syscall_64+0x69/0x1e0
> [ 1889.493152] entry_SYSCALL64_slow_path+0x25/0x25
> [ 1889.497771] RIP: 0033:0x7f18ee784a11
> [ 1889.501341] RSP: 002b:7ffd56942618 EFLAGS: 0246 ORIG_RAX:
>
> [ 1889.508897] RAX: ffda RBX: 559a9ae6d260 RCX:
> 7f18ee784a11
> [ 1889.516022] RDX: 1000 RSI: 559a9ae80f70 RDI:
> 0008
> [ 1889.523145] RBP: 0d68 R08: 0003 R09:
> ffb0
> [ 1889.530270] R10: 1000 R11: 0246 R12:
> 7f18eea4b700
> [ 1889.537395] R13: 7f18eea4c240 R14: 559a9ae6d260 R15:
>
> [ 1889.544518] Code: 44 00 00 0f 1f 44 00 00 48 81 ff c8 f7 ff ff 55 53 48 89
> fb 74 4c 48 8b 9b 38 08 00 00 48 85 db 74 7c 48 8b 5b 50 48 85 db 74 63 <48>
> 83 bb b0 00 00 00 00 74 2a 48 c7 c5 60 2e 1e a9 48 89 df e8
> [ 1889.563368] RIP:
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
FWIW, I can do "cat" . I get a single number seemingly followed by an infinite stream of 0s (I tried wc -l, but did not want to wait very long and killed it). Here is what it looks like, if limited by "head": root@gdansk ~ # cat '/sys/fs/cgroup/unified/machine.slice/machine-qemu\x2d1\x2dkartuzy\x2dspice.scope/cgroup.procs' | head 10649 0 0 0 0 0 0 0 0 0 root@gdansk ~ # PID 10649 is indeed qemu process running the virtual machine in question: root@gdansk ~ # ps lw 10649 F UID PID PPID PRI NIVSZ RSS WCHAN STAT TTYTIME COMMAND 6 0 10649 1 20 0 4815836 60252 - Sl ? 2:56 /usr/bin/qemu-system-x86_64 -name guest=kartuzy-spice,process=qemu:kartuzy-spice,debug-threads=on -S -object se Sorry about taint by ZFS, but there is nothing I can do, it is my root filesystem. Since I am the only user of the package in question I could cheat and replace the license for the build of the ZFS module, but I do not see how that might help. B.
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
FWIW, I can do "cat" . I get a single number seemingly followed by an infinite stream of 0s (I tried wc -l, but did not want to wait very long and killed it). Here is what it looks like, if limited by "head": root@gdansk ~ # cat '/sys/fs/cgroup/unified/machine.slice/machine-qemu\x2d1\x2dkartuzy\x2dspice.scope/cgroup.procs' | head 10649 0 0 0 0 0 0 0 0 0 root@gdansk ~ # PID 10649 is indeed qemu process running the virtual machine in question: root@gdansk ~ # ps lw 10649 F UID PID PPID PRI NIVSZ RSS WCHAN STAT TTYTIME COMMAND 6 0 10649 1 20 0 4815836 60252 - Sl ? 2:56 /usr/bin/qemu-system-x86_64 -name guest=kartuzy-spice,process=qemu:kartuzy-spice,debug-threads=on -S -object se Sorry about taint by ZFS, but there is nothing I can do, it is my root filesystem. Since I am the only user of the package in question I could cheat and replace the license for the build of the ZFS module, but I do not see how that might help. B.
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On 12/17/2017 10:30 AM, Bronek Kozicki wrote:
> On 17/12/2017 18:25, Randy Dunlap wrote:
>> On 12/17/2017 09:49 AM, Bronek Kozicki wrote:
>>> I just upgraded to 4.14.7 and tried to reproduce this error, this time
>>> under strace. As you can see this happens when systemctl tries to read a
>>> specific entry under /sys/fs . In case this matters, the entry is for a
>>> small virtual machine running under qemu/kvm and managed by libvirt.
>>>
>>> open("/sys/fs/cgroup/unified/machine.slice",
>>> O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
>>> fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
>>> getdents(5, /* 12 entries */, 32768) = 464
>>> openat(AT_FDCWD,
>>> "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
>>> O_RDONLY|O_CLOEXEC) = 8
>>> fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
>>> read(8, ) = ?
>>> +++ killed by SIGKILL +++
>>> [1] 12078 killed strace -- systemctl status
>>>
>>>
>>> B.
>>>
>>
>> Hi,
>>
>> Can you reproduce this without using (loading) the XFS modules?
>> They cause the kernel to be tainted.
>
> I think you mean ZFS - I cannot do that. It is my root filesystem.
Sorry, yes, I did mean ZFS.
thanks,
--
~Randy
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On 12/17/2017 10:30 AM, Bronek Kozicki wrote:
> On 17/12/2017 18:25, Randy Dunlap wrote:
>> On 12/17/2017 09:49 AM, Bronek Kozicki wrote:
>>> I just upgraded to 4.14.7 and tried to reproduce this error, this time
>>> under strace. As you can see this happens when systemctl tries to read a
>>> specific entry under /sys/fs . In case this matters, the entry is for a
>>> small virtual machine running under qemu/kvm and managed by libvirt.
>>>
>>> open("/sys/fs/cgroup/unified/machine.slice",
>>> O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
>>> fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
>>> getdents(5, /* 12 entries */, 32768) = 464
>>> openat(AT_FDCWD,
>>> "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
>>> O_RDONLY|O_CLOEXEC) = 8
>>> fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
>>> read(8, ) = ?
>>> +++ killed by SIGKILL +++
>>> [1] 12078 killed strace -- systemctl status
>>>
>>>
>>> B.
>>>
>>
>> Hi,
>>
>> Can you reproduce this without using (loading) the XFS modules?
>> They cause the kernel to be tainted.
>
> I think you mean ZFS - I cannot do that. It is my root filesystem.
Sorry, yes, I did mean ZFS.
thanks,
--
~Randy
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On 17/12/2017 18:25, Randy Dunlap wrote:
On 12/17/2017 09:49 AM, Bronek Kozicki wrote:
I just upgraded to 4.14.7 and tried to reproduce this error, this time under
strace. As you can see this happens when systemctl tries to read a specific
entry under /sys/fs . In case this matters, the entry is for a small virtual
machine running under qemu/kvm and managed by libvirt.
open("/sys/fs/cgroup/unified/machine.slice",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
getdents(5, /* 12 entries */, 32768) = 464
openat(AT_FDCWD,
"/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
O_RDONLY|O_CLOEXEC) = 8
fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
read(8, ) = ?
+++ killed by SIGKILL +++
[1] 12078 killed strace -- systemctl status
B.
Hi,
Can you reproduce this without using (loading) the XFS modules?
They cause the kernel to be tainted.
I think you mean ZFS - I cannot do that. It is my root filesystem.
B.
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On 17/12/2017 18:25, Randy Dunlap wrote:
On 12/17/2017 09:49 AM, Bronek Kozicki wrote:
I just upgraded to 4.14.7 and tried to reproduce this error, this time under
strace. As you can see this happens when systemctl tries to read a specific
entry under /sys/fs . In case this matters, the entry is for a small virtual
machine running under qemu/kvm and managed by libvirt.
open("/sys/fs/cgroup/unified/machine.slice",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
getdents(5, /* 12 entries */, 32768) = 464
openat(AT_FDCWD,
"/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
O_RDONLY|O_CLOEXEC) = 8
fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
read(8, ) = ?
+++ killed by SIGKILL +++
[1] 12078 killed strace -- systemctl status
B.
Hi,
Can you reproduce this without using (loading) the XFS modules?
They cause the kernel to be tainted.
I think you mean ZFS - I cannot do that. It is my root filesystem.
B.
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On 12/17/2017 09:49 AM, Bronek Kozicki wrote:
> I just upgraded to 4.14.7 and tried to reproduce this error, this time under
> strace. As you can see this happens when systemctl tries to read a specific
> entry under /sys/fs . In case this matters, the entry is for a small virtual
> machine running under qemu/kvm and managed by libvirt.
>
> open("/sys/fs/cgroup/unified/machine.slice",
> O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> getdents(5, /* 12 entries */, 32768) = 464
> openat(AT_FDCWD,
> "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> O_RDONLY|O_CLOEXEC) = 8
> fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> read(8, ) = ?
> +++ killed by SIGKILL +++
> [1] 12078 killed strace -- systemctl status
>
>
> B.
>
Hi,
Can you reproduce this without using (loading) the XFS modules?
They cause the kernel to be tainted.
Adding cgroups mailing list also.
>
> [ 1889.226051]
>
> [ 1889.235286] UBSAN: Undefined behaviour in kernel/cgroup/pids.c:67:9
> [ 1889.241563] member access within null pointer of type 'struct pids_cgroup'
> [ 1889.249920]
>
> [ 1889.259698] BUG: unable to handle kernel NULL pointer dereference at
> 00b0
> [ 1889.267524] IP: pids_free+0x28/0xb0
> [ 1889.272394] PGD 0 P4D 0
> [ 1889.274925] Oops: [#1] SMP
> [ 1889.278061] Modules linked in: ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter devlink joydev hid_logitech_hidpp mxm_wmi
> intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel
> kvm crct10dif_pclmul crc32_pclmu
> l crc32c_intel ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd
> glue_helper cryptd ext4 intel_cstate crc16 mbcache jbd2 fscrypto
> nls_iso8859_1 nls_cp437 evdev input_leds led_class vfat fat intel_rapl_perf
> mac_hid pcspkr hid_logitech_dj igb ptp mei_me pps_
> core i2c_i801 i2c_algo_bit mei lpc_ich ioatdma tpm_tis tpm_tis_core dca
> shpchp tpm wmi button sch_fq_codel sg ip_tables x_tables usbhid hid zfs(PO)
> zunicode(PO) zavl(PO) icp(PO) sd_mod serio_raw atkbd libps2 isci ahci libsas
> libahci xhci_pci ehci_pci mpt3sas xhci_hc
> d ehci_hcd raid_class libata
> [ 1889.349864] scsi_transport_sas usbcore scsi_mod usb_common i8042 serio
> zcommon(PO) znvpair(PO) spl(O) nvme nvme_core bridge stp llc vhost_net tun
> tap vhost vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio
> [ 1889.368439] CPU: 1 PID: 12084 Comm: systemctl Tainted: P W O
> 4.14.7-1-ARCH #1
> [ 1889.376525] Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014
> [ 1889.383474] task: 93149aaec140 task.stack: a88c3836c000
> [ 1889.389387] RIP: 0010:pids_free+0x28/0xb0
> [ 1889.393388] RSP: 0018:a88c3836fcc8 EFLAGS: 00010282
> [ 1889.398605] RAX: RBX: RCX:
> 0006
> [ 1889.405731] RDX: RSI: 0202 RDI:
> 0202
> [ 1889.412854] RBP: 931499ab2d58 R08: 079a R09:
>
> [ 1889.419979] R10: 001f5954 R11: 0003d040 R12:
> 56e21a48
> [ 1889.427102] R13: a91de5c0 R14: 93247b0598c0 R15:
> a91cd0a0
> [ 1889.434227] FS: 7f18eee6b8c0() GS:931ebfa4()
> knlGS:
> [ 1889.442302] CS: 0010 DS: ES: CR0: 80050033
> [ 1889.448041] CR2: 00b0 CR3: 000611019003 CR4:
> 001626e0
> [ 1889.455164] Call Trace:
> [ 1889.457610] cgroup_free+0xaa/0x190
> [ 1889.461095] __put_task_struct+0x68/0x230
> [ 1889.465105] ? seq_printf+0x4e/0x70
> [ 1889.468591] css_task_iter_next+0x74/0x90
> [ 1889.472594] kernfs_seq_next+0x58/0x110
> [ 1889.476424] seq_read+0x36c/0x620
> [ 1889.479735] __vfs_read+0x54/0x2e0
> [ 1889.483134] vfs_read+0x9d/0x200
> [ 1889.486358] SyS_read+0x52/0xc0
> [ 1889.489494] do_syscall_64+0x69/0x1e0
> [ 1889.493152] entry_SYSCALL64_slow_path+0x25/0x25
> [ 1889.497771] RIP: 0033:0x7f18ee784a11
> [ 1889.501341] RSP: 002b:7ffd56942618 EFLAGS: 0246 ORIG_RAX:
>
> [ 1889.508897] RAX: ffda RBX: 559a9ae6d260 RCX:
> 7f18ee784a11
> [ 1889.516022] RDX: 1000 RSI: 559a9ae80f70 RDI:
> 0008
> [ 1889.523145] RBP: 0d68 R08: 0003 R09:
> ffb0
> [ 1889.530270] R10: 1000 R11: 0246 R12:
> 7f18eea4b700
> [ 1889.537395] R13: 7f18eea4c240 R14: 559a9ae6d260 R15:
>
> [ 1889.544518] Code: 44 00 00 0f 1f 44 00 00 48 81 ff c8 f7 ff ff 55 53 48 89
> fb 74 4c 48 8b 9b 38 08 00 00 48 85 db 74 7c 48 8b 5b 50 48 85 db 74 63 <48>
> 83 bb b0 00 00 00 00 74 2a 48 c7 c5 60 2e 1e a9 48 89 df e8
> [ 1889.563368] RIP:
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
On 12/17/2017 09:49 AM, Bronek Kozicki wrote:
> I just upgraded to 4.14.7 and tried to reproduce this error, this time under
> strace. As you can see this happens when systemctl tries to read a specific
> entry under /sys/fs . In case this matters, the entry is for a small virtual
> machine running under qemu/kvm and managed by libvirt.
>
> open("/sys/fs/cgroup/unified/machine.slice",
> O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
> fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
> getdents(5, /* 12 entries */, 32768) = 464
> openat(AT_FDCWD,
> "/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
> O_RDONLY|O_CLOEXEC) = 8
> fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
> read(8, ) = ?
> +++ killed by SIGKILL +++
> [1] 12078 killed strace -- systemctl status
>
>
> B.
>
Hi,
Can you reproduce this without using (loading) the XFS modules?
They cause the kernel to be tainted.
Adding cgroups mailing list also.
>
> [ 1889.226051]
>
> [ 1889.235286] UBSAN: Undefined behaviour in kernel/cgroup/pids.c:67:9
> [ 1889.241563] member access within null pointer of type 'struct pids_cgroup'
> [ 1889.249920]
>
> [ 1889.259698] BUG: unable to handle kernel NULL pointer dereference at
> 00b0
> [ 1889.267524] IP: pids_free+0x28/0xb0
> [ 1889.272394] PGD 0 P4D 0
> [ 1889.274925] Oops: [#1] SMP
> [ 1889.278061] Modules linked in: ebtable_filter ebtables ip6table_filter
> ip6_tables iptable_filter devlink joydev hid_logitech_hidpp mxm_wmi
> intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel
> kvm crct10dif_pclmul crc32_pclmu
> l crc32c_intel ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd
> glue_helper cryptd ext4 intel_cstate crc16 mbcache jbd2 fscrypto
> nls_iso8859_1 nls_cp437 evdev input_leds led_class vfat fat intel_rapl_perf
> mac_hid pcspkr hid_logitech_dj igb ptp mei_me pps_
> core i2c_i801 i2c_algo_bit mei lpc_ich ioatdma tpm_tis tpm_tis_core dca
> shpchp tpm wmi button sch_fq_codel sg ip_tables x_tables usbhid hid zfs(PO)
> zunicode(PO) zavl(PO) icp(PO) sd_mod serio_raw atkbd libps2 isci ahci libsas
> libahci xhci_pci ehci_pci mpt3sas xhci_hc
> d ehci_hcd raid_class libata
> [ 1889.349864] scsi_transport_sas usbcore scsi_mod usb_common i8042 serio
> zcommon(PO) znvpair(PO) spl(O) nvme nvme_core bridge stp llc vhost_net tun
> tap vhost vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio
> [ 1889.368439] CPU: 1 PID: 12084 Comm: systemctl Tainted: P W O
> 4.14.7-1-ARCH #1
> [ 1889.376525] Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014
> [ 1889.383474] task: 93149aaec140 task.stack: a88c3836c000
> [ 1889.389387] RIP: 0010:pids_free+0x28/0xb0
> [ 1889.393388] RSP: 0018:a88c3836fcc8 EFLAGS: 00010282
> [ 1889.398605] RAX: RBX: RCX:
> 0006
> [ 1889.405731] RDX: RSI: 0202 RDI:
> 0202
> [ 1889.412854] RBP: 931499ab2d58 R08: 079a R09:
>
> [ 1889.419979] R10: 001f5954 R11: 0003d040 R12:
> 56e21a48
> [ 1889.427102] R13: a91de5c0 R14: 93247b0598c0 R15:
> a91cd0a0
> [ 1889.434227] FS: 7f18eee6b8c0() GS:931ebfa4()
> knlGS:
> [ 1889.442302] CS: 0010 DS: ES: CR0: 80050033
> [ 1889.448041] CR2: 00b0 CR3: 000611019003 CR4:
> 001626e0
> [ 1889.455164] Call Trace:
> [ 1889.457610] cgroup_free+0xaa/0x190
> [ 1889.461095] __put_task_struct+0x68/0x230
> [ 1889.465105] ? seq_printf+0x4e/0x70
> [ 1889.468591] css_task_iter_next+0x74/0x90
> [ 1889.472594] kernfs_seq_next+0x58/0x110
> [ 1889.476424] seq_read+0x36c/0x620
> [ 1889.479735] __vfs_read+0x54/0x2e0
> [ 1889.483134] vfs_read+0x9d/0x200
> [ 1889.486358] SyS_read+0x52/0xc0
> [ 1889.489494] do_syscall_64+0x69/0x1e0
> [ 1889.493152] entry_SYSCALL64_slow_path+0x25/0x25
> [ 1889.497771] RIP: 0033:0x7f18ee784a11
> [ 1889.501341] RSP: 002b:7ffd56942618 EFLAGS: 0246 ORIG_RAX:
>
> [ 1889.508897] RAX: ffda RBX: 559a9ae6d260 RCX:
> 7f18ee784a11
> [ 1889.516022] RDX: 1000 RSI: 559a9ae80f70 RDI:
> 0008
> [ 1889.523145] RBP: 0d68 R08: 0003 R09:
> ffb0
> [ 1889.530270] R10: 1000 R11: 0246 R12:
> 7f18eea4b700
> [ 1889.537395] R13: 7f18eea4c240 R14: 559a9ae6d260 R15:
>
> [ 1889.544518] Code: 44 00 00 0f 1f 44 00 00 48 81 ff c8 f7 ff ff 55 53 48 89
> fb 74 4c 48 8b 9b 38 08 00 00 48 85 db 74 7c 48 8b 5b 50 48 85 db 74 63 <48>
> 83 bb b0 00 00 00 00 74 2a 48 c7 c5 60 2e 1e a9 48 89 df e8
> [ 1889.563368] RIP:
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
I just upgraded to 4.14.7 and tried to reproduce this error, this time under
strace. As you can see this happens when systemctl tries to read a specific
entry under /sys/fs . In case this matters, the entry is for a small virtual
machine running under qemu/kvm and managed by libvirt.
open("/sys/fs/cgroup/unified/machine.slice",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
getdents(5, /* 12 entries */, 32768)= 464
openat(AT_FDCWD,
"/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
O_RDONLY|O_CLOEXEC) = 8
fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
read(8, ) = ?
+++ killed by SIGKILL +++
[1]12078 killed strace -- systemctl status
B.
[ 1889.226051]
[ 1889.235286] UBSAN: Undefined behaviour in kernel/cgroup/pids.c:67:9
[ 1889.241563] member access within null pointer of type 'struct pids_cgroup'
[ 1889.249920]
[ 1889.259698] BUG: unable to handle kernel NULL pointer dereference at
00b0
[ 1889.267524] IP: pids_free+0x28/0xb0
[ 1889.272394] PGD 0 P4D 0
[ 1889.274925] Oops: [#1] SMP
[ 1889.278061] Modules linked in: ebtable_filter ebtables ip6table_filter
ip6_tables iptable_filter devlink joydev hid_logitech_hidpp mxm_wmi intel_rapl
sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm
crct10dif_pclmul crc32_pclmu
l crc32c_intel ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd
glue_helper cryptd ext4 intel_cstate crc16 mbcache jbd2 fscrypto nls_iso8859_1
nls_cp437 evdev input_leds led_class vfat fat intel_rapl_perf mac_hid pcspkr
hid_logitech_dj igb ptp mei_me pps_
core i2c_i801 i2c_algo_bit mei lpc_ich ioatdma tpm_tis tpm_tis_core dca shpchp
tpm wmi button sch_fq_codel sg ip_tables x_tables usbhid hid zfs(PO)
zunicode(PO) zavl(PO) icp(PO) sd_mod serio_raw atkbd libps2 isci ahci libsas
libahci xhci_pci ehci_pci mpt3sas xhci_hc
d ehci_hcd raid_class libata
[ 1889.349864] scsi_transport_sas usbcore scsi_mod usb_common i8042 serio
zcommon(PO) znvpair(PO) spl(O) nvme nvme_core bridge stp llc vhost_net tun tap
vhost vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio
[ 1889.368439] CPU: 1 PID: 12084 Comm: systemctl Tainted: PW O
4.14.7-1-ARCH #1
[ 1889.376525] Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014
[ 1889.383474] task: 93149aaec140 task.stack: a88c3836c000
[ 1889.389387] RIP: 0010:pids_free+0x28/0xb0
[ 1889.393388] RSP: 0018:a88c3836fcc8 EFLAGS: 00010282
[ 1889.398605] RAX: RBX: RCX: 0006
[ 1889.405731] RDX: RSI: 0202 RDI: 0202
[ 1889.412854] RBP: 931499ab2d58 R08: 079a R09:
[ 1889.419979] R10: 001f5954 R11: 0003d040 R12: 56e21a48
[ 1889.427102] R13: a91de5c0 R14: 93247b0598c0 R15: a91cd0a0
[ 1889.434227] FS: 7f18eee6b8c0() GS:931ebfa4()
knlGS:
[ 1889.442302] CS: 0010 DS: ES: CR0: 80050033
[ 1889.448041] CR2: 00b0 CR3: 000611019003 CR4: 001626e0
[ 1889.455164] Call Trace:
[ 1889.457610] cgroup_free+0xaa/0x190
[ 1889.461095] __put_task_struct+0x68/0x230
[ 1889.465105] ? seq_printf+0x4e/0x70
[ 1889.468591] css_task_iter_next+0x74/0x90
[ 1889.472594] kernfs_seq_next+0x58/0x110
[ 1889.476424] seq_read+0x36c/0x620
[ 1889.479735] __vfs_read+0x54/0x2e0
[ 1889.483134] vfs_read+0x9d/0x200
[ 1889.486358] SyS_read+0x52/0xc0
[ 1889.489494] do_syscall_64+0x69/0x1e0
[ 1889.493152] entry_SYSCALL64_slow_path+0x25/0x25
[ 1889.497771] RIP: 0033:0x7f18ee784a11
[ 1889.501341] RSP: 002b:7ffd56942618 EFLAGS: 0246 ORIG_RAX:
[ 1889.508897] RAX: ffda RBX: 559a9ae6d260 RCX: 7f18ee784a11
[ 1889.516022] RDX: 1000 RSI: 559a9ae80f70 RDI: 0008
[ 1889.523145] RBP: 0d68 R08: 0003 R09: ffb0
[ 1889.530270] R10: 1000 R11: 0246 R12: 7f18eea4b700
[ 1889.537395] R13: 7f18eea4c240 R14: 559a9ae6d260 R15:
[ 1889.544518] Code: 44 00 00 0f 1f 44 00 00 48 81 ff c8 f7 ff ff 55 53 48 89 fb 74
4c 48 8b 9b 38 08 00 00 48 85 db 74 7c 48 8b 5b 50 48 85 db 74 63 <48> 83 bb b0
00 00 00 00 74 2a 48 c7 c5 60 2e 1e a9 48 89 df e8
[ 1889.563368] RIP: pids_free+0x28/0xb0 RSP: a88c3836fcc8
[ 1889.568846] CR2: 00b0
[ 1889.572175] ---[ end trace eab2ed000b4d5c66 ]---
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
I just upgraded to 4.14.7 and tried to reproduce this error, this time under
strace. As you can see this happens when systemctl tries to read a specific
entry under /sys/fs . In case this matters, the entry is for a small virtual
machine running under qemu/kvm and managed by libvirt.
open("/sys/fs/cgroup/unified/machine.slice",
O_RDONLY|O_NONBLOCK|O_DIRECTORY|O_CLOEXEC) = 5
fstat(5, {st_mode=S_IFDIR|0755, st_size=0, ...}) = 0
getdents(5, /* 12 entries */, 32768)= 464
openat(AT_FDCWD,
"/sys/fs/cgroup/unified/machine.slice/machine-qemu\\x2d1\\x2dkartuzy\\x2dspice.scope/cgroup.procs",
O_RDONLY|O_CLOEXEC) = 8
fstat(8, {st_mode=S_IFREG|0644, st_size=0, ...}) = 0
read(8, ) = ?
+++ killed by SIGKILL +++
[1]12078 killed strace -- systemctl status
B.
[ 1889.226051]
[ 1889.235286] UBSAN: Undefined behaviour in kernel/cgroup/pids.c:67:9
[ 1889.241563] member access within null pointer of type 'struct pids_cgroup'
[ 1889.249920]
[ 1889.259698] BUG: unable to handle kernel NULL pointer dereference at
00b0
[ 1889.267524] IP: pids_free+0x28/0xb0
[ 1889.272394] PGD 0 P4D 0
[ 1889.274925] Oops: [#1] SMP
[ 1889.278061] Modules linked in: ebtable_filter ebtables ip6table_filter
ip6_tables iptable_filter devlink joydev hid_logitech_hidpp mxm_wmi intel_rapl
sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel kvm
crct10dif_pclmul crc32_pclmu
l crc32c_intel ghash_clmulni_intel pcbc aesni_intel aes_x86_64 crypto_simd
glue_helper cryptd ext4 intel_cstate crc16 mbcache jbd2 fscrypto nls_iso8859_1
nls_cp437 evdev input_leds led_class vfat fat intel_rapl_perf mac_hid pcspkr
hid_logitech_dj igb ptp mei_me pps_
core i2c_i801 i2c_algo_bit mei lpc_ich ioatdma tpm_tis tpm_tis_core dca shpchp
tpm wmi button sch_fq_codel sg ip_tables x_tables usbhid hid zfs(PO)
zunicode(PO) zavl(PO) icp(PO) sd_mod serio_raw atkbd libps2 isci ahci libsas
libahci xhci_pci ehci_pci mpt3sas xhci_hc
d ehci_hcd raid_class libata
[ 1889.349864] scsi_transport_sas usbcore scsi_mod usb_common i8042 serio
zcommon(PO) znvpair(PO) spl(O) nvme nvme_core bridge stp llc vhost_net tun tap
vhost vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio
[ 1889.368439] CPU: 1 PID: 12084 Comm: systemctl Tainted: PW O
4.14.7-1-ARCH #1
[ 1889.376525] Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014
[ 1889.383474] task: 93149aaec140 task.stack: a88c3836c000
[ 1889.389387] RIP: 0010:pids_free+0x28/0xb0
[ 1889.393388] RSP: 0018:a88c3836fcc8 EFLAGS: 00010282
[ 1889.398605] RAX: RBX: RCX: 0006
[ 1889.405731] RDX: RSI: 0202 RDI: 0202
[ 1889.412854] RBP: 931499ab2d58 R08: 079a R09:
[ 1889.419979] R10: 001f5954 R11: 0003d040 R12: 56e21a48
[ 1889.427102] R13: a91de5c0 R14: 93247b0598c0 R15: a91cd0a0
[ 1889.434227] FS: 7f18eee6b8c0() GS:931ebfa4()
knlGS:
[ 1889.442302] CS: 0010 DS: ES: CR0: 80050033
[ 1889.448041] CR2: 00b0 CR3: 000611019003 CR4: 001626e0
[ 1889.455164] Call Trace:
[ 1889.457610] cgroup_free+0xaa/0x190
[ 1889.461095] __put_task_struct+0x68/0x230
[ 1889.465105] ? seq_printf+0x4e/0x70
[ 1889.468591] css_task_iter_next+0x74/0x90
[ 1889.472594] kernfs_seq_next+0x58/0x110
[ 1889.476424] seq_read+0x36c/0x620
[ 1889.479735] __vfs_read+0x54/0x2e0
[ 1889.483134] vfs_read+0x9d/0x200
[ 1889.486358] SyS_read+0x52/0xc0
[ 1889.489494] do_syscall_64+0x69/0x1e0
[ 1889.493152] entry_SYSCALL64_slow_path+0x25/0x25
[ 1889.497771] RIP: 0033:0x7f18ee784a11
[ 1889.501341] RSP: 002b:7ffd56942618 EFLAGS: 0246 ORIG_RAX:
[ 1889.508897] RAX: ffda RBX: 559a9ae6d260 RCX: 7f18ee784a11
[ 1889.516022] RDX: 1000 RSI: 559a9ae80f70 RDI: 0008
[ 1889.523145] RBP: 0d68 R08: 0003 R09: ffb0
[ 1889.530270] R10: 1000 R11: 0246 R12: 7f18eea4b700
[ 1889.537395] R13: 7f18eea4c240 R14: 559a9ae6d260 R15:
[ 1889.544518] Code: 44 00 00 0f 1f 44 00 00 48 81 ff c8 f7 ff ff 55 53 48 89 fb 74
4c 48 8b 9b 38 08 00 00 48 85 db 74 7c 48 8b 5b 50 48 85 db 74 63 <48> 83 bb b0
00 00 00 00 74 2a 48 c7 c5 60 2e 1e a9 48 89 df e8
[ 1889.563368] RIP: pids_free+0x28/0xb0 RSP: a88c3836fcc8
[ 1889.568846] CR2: 00b0
[ 1889.572175] ---[ end trace eab2ed000b4d5c66 ]---
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
This has happend again, and hopefully the report is not as mangled as the previous one. I was also trying to start "systemctl status", only once this time. The kernel build is different because I've just disabled RCU tracing/debugging options. One more thing, this kernel was built with gcc 7.2.1 B. 2017-12-17T12:50:38,640725+ [ cut here ] 2017-12-17T12:50:38,640741+ WARNING: CPU: 10 PID: 16921 at kernel/fork.c:414 __put_task_struct+0x160/0x230 2017-12-17T12:50:38,640742+ Modules linked in: ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter devlink joydev hid_logitech_hidpp mxm_wmi intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel ext4 kvm crct10dif_pclmul crc32_pc lmul crc32c_intel ghash_clmulni_intel pcbc crc16 mbcache aesni_intel jbd2 aes_x86_64 crypto_simd glue_helper cryptd nls_iso8859_1 nls_cp437 vfat fscrypto fat intel_cstate evdev input_leds led_class intel_rapl_perf mac_hid pcspkr igb hid_logitech_dj ptp pps_core i2c_alg o_bit tpm_tis ioatdma mei_me i2c_i801 tpm_tis_core lpc_ich mei dca shpchp tpm wmi button sch_fq_codel sg ip_tables x_tables usbhid hid zfs(PO) zunicode(PO) zavl(PO) icp(PO) sd_mod serio_raw atkbd libps2 isci ehci_pci ahci xhci_pci libsas libahci mpt3sas xhci_hcd ehci_h cd raid_class libata 2017-12-17T12:50:38,640812+ scsi_transport_sas usbcore scsi_mod usb_common i8042 serio zcommon(PO) znvpair(PO) spl(O) nvme nvme_core bridge stp llc vhost_net tun tap vhost vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio 2017-12-17T12:50:38,640833+ CPU: 10 PID: 16921 Comm: systemctl Tainted: P O4.14.6-3-ARCH #1 2017-12-17T12:50:38,640835+ Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014 2017-12-17T12:50:38,640837+ task: 9c4b5475c140 task.stack: b4bf8641c000 2017-12-17T12:50:38,640840+ RIP: 0010:__put_task_struct+0x160/0x230 2017-12-17T12:50:38,640841+ RSP: 0018:b4bf8641fd50 EFLAGS: 00010246 2017-12-17T12:50:38,640843+ RAX: RBX: 9c4b4f2c33f8 RCX: 0001 2017-12-17T12:50:38,640845+ RDX: b4bf8641fdf8 RSI: 9c4b4f2c33f8 RDI: 9c4b4f2c33f8 2017-12-17T12:50:38,640846+ RBP: b21ddda0 R08: 000a R09: 0008 2017-12-17T12:50:38,640847+ R10: b4bf8641fcf8 R11: R12: b4bf8641fdf8 2017-12-17T12:50:38,640849+ R13: 9c4b4f2c33f8 R14: 9c4b4f2c33f8 R15: 9c655f98c578 2017-12-17T12:50:38,640851+ FS: 7fb1df5308c0() GS:9c65bfa8() knlGS: 2017-12-17T12:50:38,640852+ CS: 0010 DS: ES: CR0: 80050033 2017-12-17T12:50:38,640853+ CR2: 55e957fd6f78 CR3: 0006042fb001 CR4: 001626e0 2017-12-17T12:50:38,640855+ Call Trace: 2017-12-17T12:50:38,640862+ ? seq_printf+0x4e/0x70 2017-12-17T12:50:38,640870+ css_task_iter_next+0x74/0x90 2017-12-17T12:50:38,640876+ kernfs_seq_next+0x58/0x110 2017-12-17T12:50:38,640878+ seq_read+0x36c/0x620 2017-12-17T12:50:38,640886+ ? __handle_mm_fault+0xb10/0x1630 2017-12-17T12:50:38,640889+ __vfs_read+0x54/0x2e0 2017-12-17T12:50:38,640891+ vfs_read+0x9d/0x200 2017-12-17T12:50:38,640893+ SyS_read+0x52/0xc0 2017-12-17T12:50:38,640899+ entry_SYSCALL_64_fastpath+0x1a/0xa5 2017-12-17T12:50:38,640902+ RIP: 0033:0x7fb1dee49a11 2017-12-17T12:50:38,640903+ RSP: 002b:7ffcf8aa5268 EFLAGS: 0246 ORIG_RAX: 2017-12-17T12:50:38,640905+ RAX: ffda RBX: 7fb1df114aa0 RCX: 7fb1dee49a11 2017-12-17T12:50:38,640907+ RDX: 1000 RSI: 55e957fd5f70 RDI: 0008 2017-12-17T12:50:38,640908+ RBP: 7fb1df114b00 R08: 0003 R09: ffb0 2017-12-17T12:50:38,640909+ R10: 1000 R11: 0246 R12: 1010 2017-12-17T12:50:38,640910+ R13: 7fb1df114b00 R14: 1000 R15: 0001 2017-12-17T12:50:38,640912+ Code: 44 24 10 65 48 33 04 25 28 00 00 00 0f 85 85 00 00 00 48 83 c4 18 48 89 df 5b 5d 41 5c 41 5d e9 27 fe ff ff 0f ff e9 ee fe ff ff <0f> ff e9 d2 fe ff ff 0f ff e9 f2 fe ff ff 4d 8d ac 24 d0 03 00 2017-12-17T12:50:38,640950+ ---[ end trace bc939269a984f4e0 ]--- 2017-12-17T12:50:38,640953+ 2017-12-17T12:50:38,649395+ UBSAN: Undefined behaviour in kernel/cgroup/pids.c:67:9 2017-12-17T12:50:38,655693+ member access within null pointer of type 'struct pids_cgroup' 2017-12-17T12:50:38,662630+ CPU: 10 PID: 16921 Comm: systemctl Tainted: P W O4.14.6-3-ARCH #1 2017-12-17T12:50:38,662631+ Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014 2017-12-17T12:50:38,662632+ Call Trace: 2017-12-17T12:50:38,662638+ dump_stack+0x70/0xae 2017-12-17T12:50:38,662645+ ubsan_epilogue+0x9/0x40
Re: PROBLEM: NULL pointer dereference in kernel 4.14.6
This has happend again, and hopefully the report is not as mangled as the previous one. I was also trying to start "systemctl status", only once this time. The kernel build is different because I've just disabled RCU tracing/debugging options. One more thing, this kernel was built with gcc 7.2.1 B. 2017-12-17T12:50:38,640725+ [ cut here ] 2017-12-17T12:50:38,640741+ WARNING: CPU: 10 PID: 16921 at kernel/fork.c:414 __put_task_struct+0x160/0x230 2017-12-17T12:50:38,640742+ Modules linked in: ebtable_filter ebtables ip6table_filter ip6_tables iptable_filter devlink joydev hid_logitech_hidpp mxm_wmi intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp coretemp kvm_intel ext4 kvm crct10dif_pclmul crc32_pc lmul crc32c_intel ghash_clmulni_intel pcbc crc16 mbcache aesni_intel jbd2 aes_x86_64 crypto_simd glue_helper cryptd nls_iso8859_1 nls_cp437 vfat fscrypto fat intel_cstate evdev input_leds led_class intel_rapl_perf mac_hid pcspkr igb hid_logitech_dj ptp pps_core i2c_alg o_bit tpm_tis ioatdma mei_me i2c_i801 tpm_tis_core lpc_ich mei dca shpchp tpm wmi button sch_fq_codel sg ip_tables x_tables usbhid hid zfs(PO) zunicode(PO) zavl(PO) icp(PO) sd_mod serio_raw atkbd libps2 isci ehci_pci ahci xhci_pci libsas libahci mpt3sas xhci_hcd ehci_h cd raid_class libata 2017-12-17T12:50:38,640812+ scsi_transport_sas usbcore scsi_mod usb_common i8042 serio zcommon(PO) znvpair(PO) spl(O) nvme nvme_core bridge stp llc vhost_net tun tap vhost vfio_pci irqbypass vfio_virqfd vfio_iommu_type1 vfio 2017-12-17T12:50:38,640833+ CPU: 10 PID: 16921 Comm: systemctl Tainted: P O4.14.6-3-ARCH #1 2017-12-17T12:50:38,640835+ Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014 2017-12-17T12:50:38,640837+ task: 9c4b5475c140 task.stack: b4bf8641c000 2017-12-17T12:50:38,640840+ RIP: 0010:__put_task_struct+0x160/0x230 2017-12-17T12:50:38,640841+ RSP: 0018:b4bf8641fd50 EFLAGS: 00010246 2017-12-17T12:50:38,640843+ RAX: RBX: 9c4b4f2c33f8 RCX: 0001 2017-12-17T12:50:38,640845+ RDX: b4bf8641fdf8 RSI: 9c4b4f2c33f8 RDI: 9c4b4f2c33f8 2017-12-17T12:50:38,640846+ RBP: b21ddda0 R08: 000a R09: 0008 2017-12-17T12:50:38,640847+ R10: b4bf8641fcf8 R11: R12: b4bf8641fdf8 2017-12-17T12:50:38,640849+ R13: 9c4b4f2c33f8 R14: 9c4b4f2c33f8 R15: 9c655f98c578 2017-12-17T12:50:38,640851+ FS: 7fb1df5308c0() GS:9c65bfa8() knlGS: 2017-12-17T12:50:38,640852+ CS: 0010 DS: ES: CR0: 80050033 2017-12-17T12:50:38,640853+ CR2: 55e957fd6f78 CR3: 0006042fb001 CR4: 001626e0 2017-12-17T12:50:38,640855+ Call Trace: 2017-12-17T12:50:38,640862+ ? seq_printf+0x4e/0x70 2017-12-17T12:50:38,640870+ css_task_iter_next+0x74/0x90 2017-12-17T12:50:38,640876+ kernfs_seq_next+0x58/0x110 2017-12-17T12:50:38,640878+ seq_read+0x36c/0x620 2017-12-17T12:50:38,640886+ ? __handle_mm_fault+0xb10/0x1630 2017-12-17T12:50:38,640889+ __vfs_read+0x54/0x2e0 2017-12-17T12:50:38,640891+ vfs_read+0x9d/0x200 2017-12-17T12:50:38,640893+ SyS_read+0x52/0xc0 2017-12-17T12:50:38,640899+ entry_SYSCALL_64_fastpath+0x1a/0xa5 2017-12-17T12:50:38,640902+ RIP: 0033:0x7fb1dee49a11 2017-12-17T12:50:38,640903+ RSP: 002b:7ffcf8aa5268 EFLAGS: 0246 ORIG_RAX: 2017-12-17T12:50:38,640905+ RAX: ffda RBX: 7fb1df114aa0 RCX: 7fb1dee49a11 2017-12-17T12:50:38,640907+ RDX: 1000 RSI: 55e957fd5f70 RDI: 0008 2017-12-17T12:50:38,640908+ RBP: 7fb1df114b00 R08: 0003 R09: ffb0 2017-12-17T12:50:38,640909+ R10: 1000 R11: 0246 R12: 1010 2017-12-17T12:50:38,640910+ R13: 7fb1df114b00 R14: 1000 R15: 0001 2017-12-17T12:50:38,640912+ Code: 44 24 10 65 48 33 04 25 28 00 00 00 0f 85 85 00 00 00 48 83 c4 18 48 89 df 5b 5d 41 5c 41 5d e9 27 fe ff ff 0f ff e9 ee fe ff ff <0f> ff e9 d2 fe ff ff 0f ff e9 f2 fe ff ff 4d 8d ac 24 d0 03 00 2017-12-17T12:50:38,640950+ ---[ end trace bc939269a984f4e0 ]--- 2017-12-17T12:50:38,640953+ 2017-12-17T12:50:38,649395+ UBSAN: Undefined behaviour in kernel/cgroup/pids.c:67:9 2017-12-17T12:50:38,655693+ member access within null pointer of type 'struct pids_cgroup' 2017-12-17T12:50:38,662630+ CPU: 10 PID: 16921 Comm: systemctl Tainted: P W O4.14.6-3-ARCH #1 2017-12-17T12:50:38,662631+ Hardware name: Supermicro X9DA7/E/X9DA7/E, BIOS 3.0a 07/02/2014 2017-12-17T12:50:38,662632+ Call Trace: 2017-12-17T12:50:38,662638+ dump_stack+0x70/0xae 2017-12-17T12:50:38,662645+ ubsan_epilogue+0x9/0x40
