[LU-7003] append_context_for_mount() must quote the value of the context option

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.9.0
• Affects Version/s: Lustre 2.5.0, Lustre 2.7.0, Lustre 2.8.0
• Labels: SELinux
• Severity: 3
• Assignee: John Hammond
• Reporter: John Hammond

Description

In append_context_for_mount() the SELinux context of the temporary directory is appended to the mount options by

strcat(mop->mo_ldd.ldd_mount_opts, ",context=");
strcat(mop->mo_ldd.ldd_mount_opts, fcontext);

This is incorrect since as mount.8 notes

Warning: the context value might contain commas, in which case the  value
has to be properly quoted, otherwise mount(8) will interpret the comma as
a separator between mount options.  Don't forget that  the  shell  strips
off quotes and thus double quoting is required.  For example:

    mount -t tmpfs none /mnt -o 'context="system_u:object_r:tmp_t:s0:c127,c456",noexec'

For more details, see selinux(8).