Public bug reported: On a server machine that runs a pppoe server I have noticed a high load average on a idle machine (CPU is 90% idle). Looking at kernel logs I have found following:
------------[ cut here ]------------ kernel BUG at /build/linux-lts-wily-Ejb_ce/linux-lts-wily-4.2.0/drivers/net/ppp/ppp_generic.c:291! invalid opcode: 0000 [#1] SMP Modules linked in: btrfs xor raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c act_mirred sch_ingress cls_fw cls_u32 sch iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat xt_CT nf_conntrack iptable_raw ipt_REJECT nf_reject_ipv4 xt_tcpudp iptab p llc ebtable_filter ebtables x_tables ppdev kvm_intel kvm crct10dif_pclmul crc32_pclmul aesni_intel aes_x86_64 lrw gf128mul glue_helper pvpanic lp 8250_fintek parport_pc parport cirrus ttm drm_kms_helper mac_hid drm syscopyarea sysfillrect sysimgblt i2c_piix4 psmouse flop CPU: 0 PID: 1667 Comm: pppd Not tainted 4.2.0-42-generic #49~14.04.1-Ubuntu Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff8800660a3700 ti: ffff88002f36c000 task.ti: ffff88002f36c000 RIP: 0010:[<ffffffff817bdbc9>] [<ffffffff817bdbc9>] ppp_pernet.part.16+0x4/0x6 RSP: 0018:ffff88002f36fdf8 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 000000004004743a RCX: 000000000065b528 RDX: 00000000000001c3 RSI: 000000004004743a RDI: ffffffff81cdd580 RBP: ffff88002f36fdf8 R08: 0000000000000000 R09: 00000000020c84e0 R10: 00007ffcefbbf610 R11: 0000000000000246 R12: ffff880021176900 R13: ffff880021176500 R14: 000000000065b528 R15: 000000000065b528 FS: 00007fb63fc07740(0000) GS:ffff88007fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5bbfeb5000 CR3: 0000000069b49000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Stack: ffff88002f36fe78 ffffffff8159e7fa ffffffff81cede80 ffffffff000001c3 ffff880036567ca8 00000000000001c3 8080808080808080 0000000000000000 00000000fffffe00 ffffffff8120b324 0000000000000001 ffff880021176500 Call Trace: [<ffffffff8159e7fa>] ppp_ioctl+0xdca/0xde0 [<ffffffff8120b324>] ? __fd_install+0x24/0xc0 [<ffffffff8120116d>] do_vfs_ioctl+0x2cd/0x4b0 [<ffffffff811fd12f>] ? putname+0x5f/0x70 [<ffffffff810c0f71>] ? __raw_callee_save___pv_queued_spin_unlock+0x11/0x20 [<ffffffff812013c9>] SyS_ioctl+0x79/0x90 [<ffffffff817c36f2>] entry_SYSCALL_64_fastpath+0x16/0x75 Code: 00 00 00 48 c7 c7 58 9a a9 81 48 89 e5 e8 b0 be 8b ff 5d c6 05 97 97 54 00 01 c3 55 48 89 e5 0f 0b 55 48 89 e5 0f 0b 55 48 89 e5 <0f> 0b 55 48 89 e5 0f 0b 0f 1f 44 00 00 55 48 c7 c7 20 d7 cd 81 RIP [<ffffffff817bdbc9>] ppp_pernet.part.16+0x4/0x6 RSP <ffff88002f36fdf8> ---[ end trace e5e2f1c7519e1d6c ]--- Except from unusually high load average I have noticed no other problems. But some services on a machine do monitor load average and shut down if it goes too high, so I had to reboot a machine to fix the issue. I'll be happy to give any additional information required to fix this bug. ProblemType: Bug DistroRelease: Ubuntu 14.04 Package: linux-headers-4.2.0-42 4.2.0-42.49~14.04.1 ProcVersionSignature: Ubuntu 4.2.0-42.49~14.04.1-generic 4.2.8-ckt12 Uname: Linux 4.2.0-42-generic x86_64 ApportVersion: 2.14.1-0ubuntu3.21 Architecture: amd64 Date: Thu Aug 25 12:19:02 2016 InstallationDate: Installed on 2012-07-25 (1491 days ago) InstallationMedia: Ubuntu-Server 12.04 LTS "Precise Pangolin" - Release amd64 (20120424.1) PackageArchitecture: all SourcePackage: linux-lts-wily UpgradeStatus: Upgraded to trusty on 2013-04-10 (1233 days ago) ** Affects: linux-lts-wily (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug trusty -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1616771 Title: kernel BUG in ppp_generic.c, high load average after that To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux-lts-wily/+bug/1616771/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs