The do_umount function in fs/namespace.c in the Linux kernel through 3.17 does not require the CAP_SYS_ADMIN capability for do_remount_sb calls that change the root filesystem to read-only, which allows local users to cause a denial of service (loss of writability) by making certain unshare system calls, clearing the / MNT_LOCKED flag, and making an MNT_FORCE umount system call.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Linux_kernel | Linux | * | 3.17 (including) |
| Red Hat Enterprise Linux 7 | RedHat | kernel-rt-0:3.10.0-693.rt56.617.el7 | * |
| Red Hat Enterprise Linux 7 | RedHat | kernel-0:3.10.0-693.el7 | * |
| Linux | Ubuntu | lucid | * |
| Linux | Ubuntu | precise | * |
| Linux | Ubuntu | trusty | * |
| Linux | Ubuntu | upstream | * |
| Linux | Ubuntu | utopic | * |
| Linux-2.6 | Ubuntu | upstream | * |
| Linux-armadaxp | Ubuntu | precise | * |
| Linux-armadaxp | Ubuntu | upstream | * |
| Linux-aws | Ubuntu | upstream | * |
| Linux-ec2 | Ubuntu | lucid | * |
| Linux-ec2 | Ubuntu | upstream | * |
| Linux-flo | Ubuntu | esm-apps/xenial | * |
| Linux-flo | Ubuntu | trusty | * |
| Linux-flo | Ubuntu | upstream | * |
| Linux-flo | Ubuntu | utopic | * |
| Linux-flo | Ubuntu | vivid | * |
| Linux-flo | Ubuntu | vivid/stable-phone-overlay | * |
| Linux-flo | Ubuntu | wily | * |
| Linux-flo | Ubuntu | xenial | * |
| Linux-flo | Ubuntu | yakkety | * |
| Linux-fsl-imx51 | Ubuntu | lucid | * |
| Linux-fsl-imx51 | Ubuntu | upstream | * |
| Linux-gke | Ubuntu | upstream | * |
| Linux-goldfish | Ubuntu | esm-apps/xenial | * |
| Linux-goldfish | Ubuntu | trusty | * |
| Linux-goldfish | Ubuntu | upstream | * |
| Linux-goldfish | Ubuntu | utopic | * |
| Linux-goldfish | Ubuntu | vivid | * |
| Linux-goldfish | Ubuntu | wily | * |
| Linux-goldfish | Ubuntu | xenial | * |
| Linux-goldfish | Ubuntu | yakkety | * |
| Linux-goldfish | Ubuntu | zesty | * |
| Linux-grouper | Ubuntu | trusty | * |
| Linux-grouper | Ubuntu | upstream | * |
| Linux-grouper | Ubuntu | utopic | * |
| Linux-hwe | Ubuntu | upstream | * |
| Linux-hwe-edge | Ubuntu | upstream | * |
| Linux-linaro-omap | Ubuntu | precise | * |
| Linux-linaro-omap | Ubuntu | upstream | * |
| Linux-linaro-shared | Ubuntu | precise | * |
| Linux-linaro-shared | Ubuntu | upstream | * |
| Linux-linaro-vexpress | Ubuntu | precise | * |
| Linux-linaro-vexpress | Ubuntu | upstream | * |
| Linux-lts-quantal | Ubuntu | precise | * |
| Linux-lts-quantal | Ubuntu | upstream | * |
| Linux-lts-raring | Ubuntu | precise | * |
| Linux-lts-raring | Ubuntu | precise/esm | * |
| Linux-lts-raring | Ubuntu | upstream | * |
| Linux-lts-saucy | Ubuntu | precise | * |
| Linux-lts-saucy | Ubuntu | upstream | * |
| Linux-lts-trusty | Ubuntu | precise | * |
| Linux-lts-trusty | Ubuntu | upstream | * |
| Linux-lts-utopic | Ubuntu | upstream | * |
| Linux-lts-vivid | Ubuntu | upstream | * |
| Linux-lts-wily | Ubuntu | upstream | * |
| Linux-lts-xenial | Ubuntu | upstream | * |
| Linux-maguro | Ubuntu | trusty | * |
| Linux-maguro | Ubuntu | upstream | * |
| Linux-mako | Ubuntu | esm-apps/xenial | * |
| Linux-mako | Ubuntu | trusty | * |
| Linux-mako | Ubuntu | upstream | * |
| Linux-mako | Ubuntu | utopic | * |
| Linux-mako | Ubuntu | vivid | * |
| Linux-mako | Ubuntu | vivid/stable-phone-overlay | * |
| Linux-mako | Ubuntu | wily | * |
| Linux-mako | Ubuntu | xenial | * |
| Linux-mako | Ubuntu | yakkety | * |
| Linux-manta | Ubuntu | trusty | * |
| Linux-manta | Ubuntu | upstream | * |
| Linux-manta | Ubuntu | utopic | * |
| Linux-manta | Ubuntu | vivid | * |
| Linux-manta | Ubuntu | wily | * |
| Linux-mvl-dove | Ubuntu | lucid | * |
| Linux-mvl-dove | Ubuntu | upstream | * |
| Linux-qcm-msm | Ubuntu | lucid | * |
| Linux-qcm-msm | Ubuntu | precise | * |
| Linux-qcm-msm | Ubuntu | upstream | * |
| Linux-raspi2 | Ubuntu | upstream | * |
| Linux-raspi2 | Ubuntu | vivid/ubuntu-core | * |
| Linux-snapdragon | Ubuntu | upstream | * |
| Linux-ti-omap4 | Ubuntu | precise | * |
| Linux-ti-omap4 | Ubuntu | upstream | * |