** Description changed: == SRU Justification == Currently, when writing echo 18446744073709551616 > /proc/sys/fs/file-max - /proc/sys/fs/file-max will overflow and be set to 0 and crashed the - system. + /proc/sys/fs/file-max will overflow and be set to 0 and make the system + stuck with "Too many open files in system" error within seconds. The upper and lower limit need to be defined properly to avoid this. This failure was reported by the case 2 and 3 of the sysctl02 test in LTP: sysctl02 2 TFAIL: /proc/sys/fs/file-max overflows and set to 18446744073709551615 sysctl02 3 TFAIL: /proc/sys/fs/file-max overflows and set to 9223372036854775808 == Fix == * 32a5ad9c sysctl: handle overflow for file-max * 9002b214 kernel/sysctl.c: fix out-of-bounds access when setting file-max These patches can be cherry-picked into B/C. They have already been applied in X/D from stable update process. == Test == Test kernel could be found here: https://people.canonical.com/~phlin/kernel/lp-1834310-file-max/ Tested OK on KVM nodes with the following command (extracted from the sysctl02 test case in LTP): - $ cat /proc/sys/fs/file-max - $ sudo sysctl -w -q fs.file-max=18446744073709551615 - $ cat /proc/sys/fs/file-max - $ sudo sysctl -w -q fs.file-max=9223372036854775808 - $ cat /proc/sys/fs/file-max + $ cat /proc/sys/fs/file-max + $ sudo sysctl -w -q fs.file-max=18446744073709551615 + $ cat /proc/sys/fs/file-max + $ sudo sysctl -w -q fs.file-max=9223372036854775808 + $ cat /proc/sys/fs/file-max All three file-max output should be identical with the patched kernel. This is because the file-max value is parsed via __do_proc_doulongvec_minmax(), which does not report error when min or max are exceeded but it will just keep the old value instead. == Regression Potential == Low, just adding boundaries to the file-max. And it's been applied in some of our kernels for a while. - ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-52-generic 4.15.0-52.56 ProcVersionSignature: User Name 4.15.0-52.56-generic 4.15.18 Uname: Linux 4.15.0-52-generic x86_64 AlsaDevices: total 0 crw-rw---- 1 root audio 116, 1 Jun 25 11:03 seq crw-rw---- 1 root audio 116, 33 Jun 25 11:03 timer AplayDevices: Error: [Errno 2] No such file or directory: 'aplay': 'aplay' ApportVersion: 2.20.9-0ubuntu7.6 Architecture: amd64 ArecordDevices: Error: [Errno 2] No such file or directory: 'arecord': 'arecord' AudioDevicesInUse: Error: command ['fuser', '-v', '/dev/snd/seq', '/dev/snd/timer'] failed with exit code 1: Date: Tue Jun 25 11:04:55 2019 IwConfig: Error: [Errno 2] No such file or directory: 'iwconfig': 'iwconfig' Lsusb: Bus 001 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub MachineType: QEMU Standard PC (i440FX + PIIX, 1996) PciMultimedia: ProcFB: 0 cirrusdrmfb ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-4.15.0-52-generic root=UUID=6f08d1c2-d443-47ee-97ca-2aeb1bf53f35 ro RelatedPackageVersions: linux-restricted-modules-4.15.0-52-generic N/A linux-backports-modules-4.15.0-52-generic N/A linux-firmware 1.173.6 RfKill: Error: [Errno 2] No such file or directory: 'rfkill': 'rfkill' SourcePackage: linux UpgradeStatus: No upgrade log present (probably fresh install) dmi.bios.date: 04/01/2014 dmi.bios.vendor: SeaBIOS dmi.bios.version: Ubuntu-1.8.2-1ubuntu1 dmi.chassis.type: 1 dmi.chassis.vendor: QEMU dmi.chassis.version: pc-i440fx-xenial dmi.modalias: dmi:bvnSeaBIOS:bvrUbuntu-1.8.2-1ubuntu1:bd04/01/2014:svnQEMU:pnStandardPC(i440FX+PIIX,1996):pvrpc-i440fx-xenial:cvnQEMU:ct1:cvrpc-i440fx-xenial: dmi.product.name: Standard PC (i440FX + PIIX, 1996) dmi.product.version: pc-i440fx-xenial dmi.sys.vendor: QEMU
-- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1834310 Title: Handle overflow for file-max To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1834310/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
