From: Jan Kara <jack@suse.cz>
Date: Tue, 7 Apr 2020 15:46:43 +0000 (+0200)
Subject: ucount: Make sure ucounts in /proc/sys/user don't regress again
X-Git-Tag: v5.10.7~2804^2
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=0f538e3e712a517bd351607de50cd298102c7c08;p=platform%2Fkernel%2Flinux-rpi.git

ucount: Make sure ucounts in /proc/sys/user don't regress again

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(). This problem got fixed in commit
eeec26d5da82 "time/namespace: Add max_time_namespaces ucount".

Add BUILD_BUG_ON to catch a similar problem in the future.

Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Andrei Vagin <avagin@gmail.com>
Link: https://lkml.kernel.org/r/20200407154643.10102-1-jack@suse.cz
---

diff --git a/kernel/ucount.c b/kernel/ucount.c
index 29c60eb..11b1596 100644
--- a/kernel/ucount.c
+++ b/kernel/ucount.c
@@ -82,6 +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) {