*** This bug is a security vulnerability *** You have been subscribed to a public security bug by Seth Arnold (seth-arnold):
CPU stuck were discovered at task hung in do_truncate. The problem was originally found by syzbot, https://syzkaller.appspot.com/bug?id=18b2ab4c697021ee8369. It is reproduced by the root user in the docker container or host on Ubuntu 20.04.3 LTS with Linux 5.4.0-91-generic. The bug reproducer is built from https://raw.githubusercontent.com/dvyukov/syzkaller-repros/master/linux/18b2ab4c697021ee8369.c. It reproduces in Ubuntu 18.04.6 LTSwith Linux 4.15.0-163-generic and Ubuntu 20.04.3 LTS with Linux mainline v5.16-rc4 also. I used MSI GT72 6QD Dominator with i7-6820HK. There are steps to reproduce in the Docker container: ----------------------------------------------------------- docker pull ubuntu docker run -ti ubuntu bash apt update apt install gcc wget wget https://raw.githubusercontent.com/dvyukov/syzkaller-repros/master/linux/18b2ab4c697021ee8369.c gcc ./18b2ab4c697021ee8369.c -static -pthread -o 18b2ab4c697021ee8369 ./18b2ab4c697021ee8369 The kernel crash contains as a result: ---------------------------------------- root@de45b02a83c0:/# ./18b2ab4c697021ee8369 �� @cgroup.controllers�./file0[ 7977.039018] watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [18b2ab4c697021e:4427] [ 8005.212380] watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [18b2ab4c697021e:4427] [ 8012.900740] rcu: INFO: rcu_sched detected stalls on CPUs/tasks: [ 8012.904199] rcu: 1-....: (148 ticks this GP) idle=db2/1/0x4000000000000004 softirq=30262/30262 fqs=7456 �� @cgroup.controllers�./file0�� @cgroup.controllers�./file0[ 8097.026740] watchdog: BUG: soft lockup - CPU#1 stuck for 22s! [apport:33113] [ 8181.189733] watchdog: BUG: soft lockup - CPU#1 stuck for 23s! [kworker/1:0:1478] ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-image-5.4.0-91-generic 5.4.0-91.102 ProcVersionSignature: Ubuntu 5.4.0-91.102-generic 5.4.151 Uname: Linux 5.4.0-91-generic x86_64 AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Dec 7 14:39 seq crw-rw---- 1 root audio 116, 33 Dec 7 14:39 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay' ApportVersion: 2.20.11-0ubuntu27.21 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: CasperMD5CheckResult: pass Date: Tue Dec 7 15:11:42 2021 InstallationDate: Installed on 2021-11-29 (8 days ago) InstallationMedia: Ubuntu-Server 20.04.3 LTS "Focal Fossa" - Release amd64 (20210824) IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig' Lsusb: Error: command ['lsusb'] failed with exit code 1: Lsusb-t: Lsusb-v: Error: command ['lsusb', '-v'] failed with exit code 1: MachineType: QEMU Standard PC (i440FX + PIIX, 1996) PciMultimedia: ProcEnviron: TERM=vt220 PATH=(custom, no user) XDG_RUNTIME_DIR=<set> LANG=C.UTF-8 SHELL=/bin/bash ProcFB: 0 bochs-drmdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.4.0-91-generic root=UUID=2ad85404-d6b7-4c7d-a860-b873557a175c ro console=ttyS0 slub_debug=FZ crashkernel=256M RelatedPackageVersions: linux-restricted-modules-5.4.0-91-generic N/A linux-backports-modules-5.4.0-91-generic N/A linux-firmware 1.187.20 RfKill: Error: [Errno 2] No such file or directory: 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/01/2014 dmi.bios.vendor: SeaBIOS dmi.bios.version: 1.13.0-1ubuntu1.1 dmi.chassis.type: 1 dmi.chassis.vendor: QEMU dmi.chassis.version: pc-i440fx-focal dmi.modalias: dmi:bvnSeaBIOS:bvr1.13.0-1ubuntu1.1:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-focal:cvnQEMU:ct1:cvrpc-i440fx-focal: dmi.product.name: Standard PC (i440FX + PIIX, 1996) dmi.product.version: pc-i440fx-focal dmi.sys.vendor: QEMU ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug focal uec-images -- CPU stuck https://bugs.launchpad.net/bugs/1953518 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to the bug report. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
