[LU-3890] $RUNAS does not clear supplementary GID list

• Type: Bug
• Resolution: Unresolved
• Priority: Minor
• Affects Version/s: Lustre 2.5.0, Lustre 2.15.0
• Labels: test
• Severity: 3
• Assignee: WC Triage
• Reporter: John Hammond

Description

In lustre/tests/cfg/local.sh RUNAS is defined as "runas -u $RUNAS_ID -g $RUNAS_GID". This does not clear the supplementary GID list. Hence commands invoked by RUNAS have root group rights.

# llmount.sh
# cd /mnt/lustre
# umask 0002
# touch f0
# ls -l f0
-rw-rw-r-- 1 root root 0 Sep  5 14:12 f0
# echo 'Archibald Barisol' | runas -u 500 -g 500 tee f0
running as uid/gid/euid/egid 500/500/500/500, groups:
 [tee] [f0]
Archibald Barisol
# cat f0
Archibald Barisol

I don't know of a test that is directly affected by this but I lost some time because of it today.