Since I reported this issue I have tried to debug this problem and found that the function call to 'i8k_get_fn_status' in the kernel module 'dell-smm-hwmon' (code at https://github.com/torvalds/linux/blob/master/drivers/hwmon/dell-smm-hwmon.c) is what causes low memory corruption on Dell Inspiron 3847.
This affects the procfs '/proc/i8k' interface only when kernel compiled with 'CONFIG_I8K' I have downloaded kernel module from https://github.com/torvalds/linux/blob/master/drivers/hwmon/dell-smm-hwmon.c and modified/compiled to debug/test this issue with possible fixes. A possible fix involves disallowing 'i8k_get_fn_status' calls for affected machines using a blacklist. I have attached modified kernel module code and makefile used as well as script and script output to check problem once modified module is loaded. Attachments: dell-smm-hwmon.c Makefile low_mem_corruption.sh script_output.txt I suspect this issue may affect other Dell machines (not just Inspiron 3847) ?? (see https://bugs.launchpad.net/i8kutils/+bug/1179282/comments/41) During the process of figuring out the likely problem I have found that the Dell SMM/BIOS seems to be buggy on various machines! Testing of modified module has been done under Ubuntu 18.04.1 LTS 4.15.0-29-generic, and 4.15.0-33-generic kernels and Linux Mint Tara 19 (4.15.0-29-generic, 4.15.0-33-generic kernels) and Linux Mint Tara 17.3 (4.4.0-134-generic, old 3.19.0-32-generic kernel) Output of tests in in attached file 'script_output.txt'. The low memory corruption problem can be reproduced on the Dell Inspiron 3847 running: Ubuntu 18.04.1 LTS, 4.15.0-32-generic Ubuntu 18.04.1 LTS, 4.15.0-33-generic Ubuntu 18.04.1 LTS, 4.19-rc1 upstream kernel (4.19.0-041900rc1) Linux Mint 19 Tara, 4.15.0-32-generic Linux Mint 19 Tara, 4.15.0-33-generic Linux Mint 17.3, OLD 3.19.0-32-generic kernel Linux Mint 17.3, 4.4.0-134-generic kernel Low memory corruption problem DOES NOT OCCUR on: Ubuntu 18.04.1 LTS, 4.15.0-29-generic Ubuntu 18.04.1 LTS, 4.15.0-30-generic Linux Mint 19 Tara, 4.15.0-29-generic I have no idea why there is different behaviour running under the different kernels noted above. Does this imply the problem may be in changes to the kernel? I am new to kernel modules and this is my first attempt at debugging one but I hope the info here is useful in fixing the problem and can be passed on to the maintainer. from https://github.com/torvalds/linux/blob/master/MAINTAINERS DELL LAPTOP SMM DRIVER M: Pali Rohár <pali.ro...@gmail.com> S: Maintained F: drivers/hwmon/dell-smm-hwmon.c ** Attachment added: "script_output.txt" https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1789519/+attachment/5185074/+files/script_output.txt -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1789519 Title: Low Memory corruption logged in syslog Status in linux package in Ubuntu: Confirmed Bug description: Dell Inspiron 3847 Desktop running Ubuntu 18.04.1 LTS kernel: 4.15.0-33-generic Corrupted low memory messages logged in syslog Can be reproduced with script: #!/bin/bash # log to syslog... logger -st low_mem_corruption.sh "Checking for low memory corruption with kernel $(uname -rv)..." # this will cause syslog messages on affected kernels... cat /proc/i8k logger -st low_mem_corruption.sh "Please wait for 90 secs to ensure low memory test has completed..." # sleep for 1.5 mins - enough time for mem check every 60 secs... sleep 90 logger -st low_mem_corruption.sh "Check for low memory corruption done! Was anything logged in syslog?" Kernels tested: Kernel 4.15.0-29-generic - fine Kernel 4.15.0-30-generic - fine Kernel 4.15.0-30-generic - Never installed, do not know - did it exist? Kernel 4.15.0-32-generic - Low Memory corruption! Kernel 4.15.0-33-generic - Low Memory corruption! ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-33-generic 4.15.0-33.36 ProcVersionSignature: Ubuntu 4.15.0-33.36-generic 4.15.18 Uname: Linux 4.15.0-33-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC0: bossman 1316 F.... pulseaudio /dev/snd/pcmC1D0p: bossman 1316 F...m pulseaudio /dev/snd/controlC1: bossman 1316 F.... pulseaudio CurrentDesktop: ubuntu:GNOME Date: Tue Aug 28 16:56:01 2018 HibernationDevice: RESUME=UUID=1c065a24-2acf-43dc-bf3d-1382f3bbf0ac InstallationDate: Installed on 2018-05-12 (108 days ago) InstallationMedia: Ubuntu 18.04 LTS "Bionic Beaver" - Release amd64 (20180426) MachineType: Dell Inc. Inspiron 3847 ProcEnviron: TERM=xterm-256color PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=en_CA.UTF-8 SHELL=/bin/bash ProcFB: 0 inteldrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-33-generic root=UUID=a5dec663-366e-4ecc-a17a-ce4219c54897 ro quiet loglevel=3 splash RelatedPackageVersions: linux-restricted-modules-4.15.0-33-generic N/A linux-backports-modules-4.15.0-33-generic N/A linux-firmware 1.173.1 SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 05/10/2018 dmi.bios.vendor: Dell Inc. dmi.bios.version: A10 dmi.board.name: 088DT1 dmi.board.vendor: Dell Inc. dmi.board.version: A01 dmi.chassis.type: 3 dmi.chassis.vendor: Dell Inc. dmi.modalias: dmi:bvnDellInc.:bvrA10:bd05/10/2018:svnDellInc.:pnInspiron3847:pvr:rvnDellInc.:rn088DT1:rvrA01:cvnDellInc.:ct3:cvr: dmi.product.family: To be filled by O.E.M. dmi.product.name: Inspiron 3847 dmi.sys.vendor: Dell Inc. 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