lxc: Set max uid/gid mappings for user namespace

There is a limit on the number of lines in the /proc/<pid>/{g,u}id_map
files. In Linux 4.14 and earlier, this limit was (arbitrarily) set at
5 lines. Since Linux 4.15, which was released on 28 Jan 2018, the limit
is 340 lines.

This change is documented in user_namespaces(7).

https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6397fac4915ab3002dc15aae751455da1a852f25

Signed-off-by: Radostin Stoyanov <rstoyanov1@gmail.com>
This commit is contained in:
Radostin Stoyanov 2018-12-15 10:02:34 +00:00 committed by Daniel P. Berrangé
parent b2485c4ad7
commit f8f525ff86

View File

@ -1390,6 +1390,13 @@ virLXCControllerSetupUsernsMap(virDomainIdMapEntryPtr map,
size_t i;
int ret = -1;
/* The kernel supports up to 340 lines in /proc/<pid>/{g,u}id_map */
if (num > 340) {
virReportError(VIR_ERR_INVALID_ARG, "%s",
_("Too many id mappings defined."));
goto cleanup;
}
for (i = 0; i < num; i++)
virBufferAsprintf(&map_value, "%u %u %u\n",
map[i].start, map[i].target, map[i].count);