Package: src:linux
Version: 3.16.7-ckt25-2+deb8u3
Severity: important
Dear Maintainer,
This is a Debian Jessie server running on Azure. Every once in a while, the
server crashes and a kernel oops is logged:
[316317.199398] BUG: unable to handle kernel NULL pointer dereference at
0000000000000038
[316317.203332] IP: [<ffffffffa0385ee3>] smb2_push_mandatory_locks+0x113/0x3c9
[cifs]
[316317.203332] PGD 3aca7c067 PUD 3c6f2a067 PMD 0
[316317.203332] Oops: 0000 [#1] SMP
[316317.203332] Modules linked in: nfnetlink_queue nfnetlink_log nfnetlink
bluetooth 6lowpan_iphc rfkill xt_tcpudp iptable_filter ip_tables x_tables
binfmt_misc tcp_diag inet_diag cmachhha25__generic arc4 ecb md4 hmac nls_utf8
cifs dns_resolver fscache hv_utils serio_raw hyperv_keyboard i2c_piix4 i2c_core
processor hyperv_fb evdev joydev thermal_sys pcspkr button autofs4 ext4 crc16
mbcache jbd2 dm_mod sg ata_generic sd_mod crc1110dif crct10dif_generic
hid_generic crct10dif_common hid_hyperv ata_piix hv_netvsc hid libata
hv_storvsc scsi_mod psmouse hv_vmbus floppy
[316317.203332] CPU: 6 PID: 44095 Comm: kworker/6:2 Not tainted 3.16.0-4-amd64
#1 Debian 3.16.7-ckt25-2+deb8u3
[316317.203332] Hardware name: Microsoft Corporation Virtual Machine/Virtual
Machine, BIOS 090006 05/23/2012
[316317.203332] Workqueue: cifsiod cifs_oplock_break [cifs]
[316317.203332] task: ffff8803bc7d1570 ti: ffff8803bc788000 task.ti:
ffff8803bc788000
[316317.203332] RIP: 0010:[<ffffffffa03852e3>] [<ffffffffa03852e3>]
smb2_push_mandatory_locks+0x113/0x3c9 [cifs]
[316317.203332] RSP: 0018:ffff8803bc78bd80 EFLAGS: 00010246
[316317.203332] RAX: 0000000000000000 RBX: ffff8801fd5faa58 RCX:
0000000000000000
[316317.203332] RDX: 0000000000000000 RSI: 0000000000000000 RDI:
ffff8803bc650000
[316317.203332] RBP: ffff8801fd5faa58 R08: 1028000000000000 R09:
ffff8803bc640000
[316317.203332] R10: fcd3d14703cb2205 R11: 0000000000000000 R12:
0000000000000aaa
[316317.203332] R13: ffff8801fd5faa40 R14: ffff880295d33000 R15:
ffff8803bc640000
[316317.203332] FS: 00007fdcf5a86700(0000) GS:ffff88045f840000(0000)
knlGS:0000000000000000
[316317.203332] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[316317.203332] CR2: 0000000000000038 CR3: 000000045788f000 CR4:
00000000000006e0
[316317.203332] Stack:
[316317.203332] ffff88030e2f7cd0 0000000000000000 ffff88030e2f7c28
0000000000031725
[316317.203332] ffff8803bc7d1570 ffff88030e2f7c30 ffff8803bc7d1570
ffff88030e2f7c40
[316317.203332] ffff880455d27ae8 ffff88030e2f7c28 ffff880295f74000
ffff88030e2f7cd0
[316317.203332] Call Trace:
[316317.203332] [<ffffffffa035e1ef>] ? cifs_oplock_break+0x10f/0x380 [cifs]
[316317.203332] [<ffffffff81081742>] ? process_one_work+0x172/0x420
[316317.203332] [<ffffffff81081dd3>] ? worker_thread+0x113/0x4f0
[316317.203332] [<ffffffff815105c1>] ? __schedule+0x2b1/0x700
[316317.203332] [<ffffffff81081cc0>] ? rescuer_thread+0x2d0/0x2d0
[316317.203332] [<ffffffff8108800d>] ? kthread+0xbd/0xe0
[316317.203332] [<ffffffff81087f50>] ? kthread_create_on_node+0x180/0x180
[316317.203332] [<ffffffff81514158>] ? ret_from_fork+0x58/0x90
[316317.203332] [<ffffffff81087f50>] ? kthread_create_on_node+0x180/0x180
[316317.203332] Code: 04 25 80 b8 00 00 48 89 44 24 20 48 89 44 24 30 0f 1f 84
00 00 00 00 00 4d 8b 75 10 49 8b 5d 18 49 8d 6d 18 49 8b 46 78 48 39 eb <48> 8b
40 38 48 89 44 24 08 0f 84 a5 00 00 00 45 31 d2 4c 89 6c
[316317.203332] RIP [<ffffffffa03852e3>] smb2_push_mandatory_locks+0x113/0x3c9
[cifs]
[316317.203332] RSP <ffff8803bc78bd80>
[316317.203332] CR2: 0000000000000038
[316317.203332] ---[ end trace c08f7fa2cf283a1e ]---
I have no idea how to reproduce the oops. I think it is load-related, even
though the load on these servers as a whole, or the CIFS mounts in particular,
is not extremely high. In total, we have nine identical machines running in
this environment (Azure cloud), three of which run production and have more
load than the other six. These three all experienced this oops one or more
times in the past 10 days or so. The less loaded machines (test environment)
haven't crashed so far. All machines have 3 CIFS mounts.
'smb2_push_mandatory_locks' seems to be suspect every time.
-- Package-specific info:
** Version:
Linux version 3.16.0-4-amd64 (debian-ker...@lists.debian.org) (gcc version
4.8.4 (Debian 4.8.4-1) ) #1 SMP Debian 3.16.7-ckt25-2+deb8u3 (2016-07-02)
** Command line:
BOOT_IMAGE=/vmlinuz initrd=/initrd.img
root=UUID=0c2f972f-e9e5-438a-a9cf-0fa537a0c2a5 console=tty0
console=ttyS0,115200 earlyprintk=ttyS0,115200
** Not tainted
** Model information
sys_vendor: Microsoft Corporation
product_name: Virtual Machine
product_version: 7.0
chassis_vendor: Microsoft Corporation
chassis_version: 7.0
bios_vendor: American Megatrends Inc.
bios_version: 090006
board_vendor: Microsoft Corporation
board_name: Virtual Machine
board_version: 7.0
** Loaded modules:
binfmt_misc
xt_tcpudp
iptable_filter
ip_tables
x_tables
tcp_diag
inet_diag
cmac
sha256_generic
arc4
ecb
md4
hmac
nls_utf8
cifs
dns_resolver
fscache
hyperv_fb
i2c_piix4
serio_raw
i2c_core
evdev
hyperv_keyboard
hv_utils
pcspkr
joydev
processor
button
thermal_sys
autofs4
ext4
crc16
mbcache
jbd2
dm_mod
sg
sd_mod
crc_t10dif
crct10dif_generic
crct10dif_common
hid_generic
ata_generic
ata_piix
hid_hyperv
hv_netvsc
libata
hv_storvsc
hid
scsi_mod
psmouse
hv_vmbus
floppy
** Network interface configuration:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
iface lo inet loopback
# The normal eth0
auto eth0
iface eth0 inet dhcp
# Maybe the VM has 2 NICs?
allow-hotplug eth1
iface eth1 inet dhcp
# Maybe the VM has 3 NICs?
allow-hotplug eth2
iface eth2 inet dhcp
** Network status:
*** IP interfaces and addresses:
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group
default
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
inet 127.0.0.1/8 scope host lo
valid_lft forever preferred_lft forever
inet6 ::1/128 scope host
valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq state UP group
default qlen 1000
link/ether 00:0d:3a:20:bd:a8 brd ff:ff:ff:ff:ff:ff
inet 10.128.1.11/24 brd 10.128.1.255 scope global eth0
valid_lft forever preferred_lft forever
inet6 fe80::20d:3aff:fe20:bda8/64 scope link
valid_lft forever preferred_lft forever
-- System Information:
Debian Release: 8.5
APT prefers stable
APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Kernel: Linux 3.16.0-4-amd64 (SMP w/8 CPU cores)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
Versions of packages linux-image-3.16.0-4-amd64 depends on:
ii debconf [debconf-2.0] 1.5.56
ii initramfs-tools [linux-initramfs-tool] 0.120+deb8u2
ii kmod 18-3
ii linux-base 3.5
Versions of packages linux-image-3.16.0-4-amd64 recommends:
ii firmware-linux-free 3.3
ii irqbalance 1.0.6-3
Versions of packages linux-image-3.16.0-4-amd64 suggests:
pn debian-kernel-handbook <none>
ii extlinux 3:6.03+dfsg-5+deb8u1
pn linux-doc-3.16 <none>
Versions of packages linux-image-3.16.0-4-amd64 is related to:
pn firmware-atheros <none>
pn firmware-bnx2 <none>
pn firmware-bnx2x <none>
pn firmware-brcm80211 <none>
pn firmware-intelwimax <none>
pn firmware-ipw2x00 <none>
pn firmware-ivtv <none>
pn firmware-iwlwifi <none>
pn firmware-libertas <none>
pn firmware-linux <none>
pn firmware-linux-nonfree <none>
pn firmware-myricom <none>
pn firmware-netxen <none>
pn firmware-qlogic <none>
pn firmware-ralink <none>
pn firmware-realtek <none>
pn xen-hypervisor <none>
-- debconf information:
linux-image-3.16.0-4-amd64/prerm/removing-running-kernel-3.16.0-4-amd64: true
linux-image-3.16.0-4-amd64/postinst/depmod-error-initrd-3.16.0-4-amd64: false
linux-image-3.16.0-4-amd64/postinst/mips-initrd-3.16.0-4-amd64:
