This repository was archived by the owner on Oct 16, 2020. It is now read-only.
This repository was archived by the owner on Oct 16, 2020. It is now read-only.
EACCES when root opens user files with O_WRONLY|O_CREAT|O_APPEND #2577
Description
Issue Report
Bug
Container Linux Version
OK on 2023.5.0
KO on 2079.1.0
KO on 2107.0.0
$ cat /etc/os-release
NAME="Container Linux by CoreOS"
ID=coreos
VERSION=2079.1.0
VERSION_ID=2079.1.0
BUILD_ID=2019-03-24-2042
PRETTY_NAME="Container Linux by CoreOS 2079.1.0 (Rhyolite)"
ANSI_COLOR="38;5;75"
HOME_URL="https://coreos.com/"
BUG_REPORT_URL="https://issues.coreos.com"
COREOS_BOARD="amd64-usr"
OK on Ubuntu with the same linux kernel as 2079.1.0 (4.19.31)
Environment
EC2
Expected Behavior
root should be able to append to any file
Actual Behavior
root gets EACCES when appending to a file owned by another regular user
Reproduction Steps
core@sand-2154-1555061726 ~ $ echo foo > /tmp/bar
core@sand-2154-1555061726 ~ $ ls -l /tmp/bar
-rw-r--r--. 1 core core 4 Apr 12 16:18 /tmp/bar
core@sand-2154-1555061726 ~ $ sudo su
sand-2154-1555061726 core # echo > /tmp/bar
bash: /tmp/bar: Permission denied
sand-2154-1555061726 core # echo >> /tmp/bar
bash: /tmp/bar: Permission denied
sand-2154-1555061726 core # cat /tmp/bar
foo
sand-2154-1555061726 core # rm /tmp/bar
sand-2154-1555061726 core # uname -a
Linux sand-2154-1555061726 4.19.31-coreos #1 SMP Sun Mar 24 20:06:59 -00 2019 x86_64 Intel(R) Xeon(R) CPU E5-2686 v4 @ 2.30GHz GenuineIntel GNU/Linux