[PATCH] ucount: Fix wrong inotify ucounts in /proc/sys/user

[PATCH] ucount: Fix wrong inotify ucounts in /proc/sys/user

[Jan Kara]

Commit 769071ac9f20 "ns: Introduce Time Namespace" broke reporting of
inotify ucounts (max_inotify_instances, max_inotify_watches) in
/proc/sys/user because it has added UCOUNT_TIME_NAMESPACES into enum
ucount_type but didn't properly update reporting in
kernel/ucount.c:setup_userns_sysctls(). Update the reporting to fix the
issue and also add BUILD_BUG_ON to catch a similar problem in the
future.

Fixes: 769071ac9f20 "ns: Introduce Time Namespace"
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 kernel/ucount.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/kernel/ucount.c b/kernel/ucount.c
index a53cc2b4179c..11b1596e2542 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -69,6 +69,7 @@ static struct ctl_table user_table[] = {
 	UCOUNT_ENTRY("max_net_namespaces"),
 	UCOUNT_ENTRY("max_mnt_namespaces"),
 	UCOUNT_ENTRY("max_cgroup_namespaces"),
+	UCOUNT_ENTRY("max_time_namespaces"),
 #ifdef CONFIG_INOTIFY_USER
 	UCOUNT_ENTRY("max_inotify_instances"),
 	UCOUNT_ENTRY("max_inotify_watches"),
@@ -81,6 +82,8 @@ bool setup_userns_sysctls(struct user_namespace *ns)
 {
 #ifdef CONFIG_SYSCTL
 	struct ctl_table *tbl;
+
+	BUILD_BUG_ON(ARRAY_SIZE(user_table) != UCOUNT_COUNTS + 1);
 	setup_sysctl_set(&ns->set, &set_root, set_is_seen);
 	tbl = kmemdup(user_table, sizeof(user_table), GFP_KERNEL);
 	if (tbl) {
-- 
2.16.4

Re: [PATCH] ucount: Fix wrong inotify ucounts in /proc/sys/user

[Thomas Gleixner]

Jan Kara <jack@suse.cz> writes:
> Commit 769071ac9f20 "ns: Introduce Time Namespace" broke reporting of
> inotify ucounts (max_inotify_instances, max_inotify_watches) in
> /proc/sys/user because it has added UCOUNT_TIME_NAMESPACES into enum
> ucount_type but didn't properly update reporting in
> kernel/ucount.c:setup_userns_sysctls(). Update the reporting to fix the
> issue and also add BUILD_BUG_ON to catch a similar problem in the
> future.

Just merged that:

  https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=timers/urgent&id=eeec26d5da8248ea4e240b8795bb4364213d3247

Could you please send a patch with just the build bug on ?

Thanks,

        tglx

Re: [PATCH] ucount: Fix wrong inotify ucounts in /proc/sys/user

[Jan Kara]

On Tue 07-04-20 16:09:39, Thomas Gleixner wrote:
> Jan Kara <jack@suse.cz> writes:
> > Commit 769071ac9f20 "ns: Introduce Time Namespace" broke reporting of
> > inotify ucounts (max_inotify_instances, max_inotify_watches) in
> > /proc/sys/user because it has added UCOUNT_TIME_NAMESPACES into enum
> > ucount_type but didn't properly update reporting in
> > kernel/ucount.c:setup_userns_sysctls(). Update the reporting to fix the
> > issue and also add BUILD_BUG_ON to catch a similar problem in the
> > future.
> 
> Just merged that:
> 
>   https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/commit/?h=timers/urgent&id=eeec26d5da8248ea4e240b8795bb4364213d3247
> 
> Could you please send a patch with just the build bug on ?

Sure, will do.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR