[PATCH 04/11] sysctl: Add size argument to init_header

From: Joel Granados <j.granados@samsung.com>
To: <mcgrof@kernel.org>, Kees Cook <keescook@chromium.org>,
	Iurii Zaikin <yzaikin@google.com>
Cc: Joel Granados <j.granados@samsung.com>,
	<linux-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>
Subject: [PATCH 04/11] sysctl: Add size argument to init_header
Date: Wed, 21 Jun 2023 11:09:53 +0200	[thread overview]
Message-ID: <20230621091000.424843-5-j.granados@samsung.com> (raw)
In-Reply-To: <20230621091000.424843-1-j.granados@samsung.com>

Pass the size of the ctl_table to properly initialize the
ctl_table_header struct. This is a preparation commit for when we start
traversing the ctl_table array with the size in ctl_table_header.
In __register_sysctl_table we use a calculated size until we add the
size argument to that function

Signed-off-by: Joel Granados <j.granados@samsung.com>
---
 fs/proc/proc_sysctl.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 93f50570eab4..09c09c373624 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -188,9 +188,10 @@ static void erase_entry(struct ctl_table_header *head, struct ctl_table *entry)
 
 static void init_header(struct ctl_table_header *head,
 	struct ctl_table_root *root, struct ctl_table_set *set,
-	struct ctl_node *node, struct ctl_table *table)
+	struct ctl_node *node, struct ctl_table *table, size_t table_size)
 {
 	head->ctl_table = table;
+	head->ctl_table_size = table_size;
 	head->ctl_table_arg = table;
 	head->used = 0;
 	head->count = 1;
@@ -973,7 +974,7 @@ static struct ctl_dir *new_dir(struct ctl_table_set *set,
 	memcpy(new_name, name, namelen);
 	table[0].procname = new_name;
 	table[0].mode = S_IFDIR|S_IRUGO|S_IXUGO;
-	init_header(&new->header, set->dir.header.root, set, node, table);
+	init_header(&new->header, set->dir.header.root, set, node, table, 1);
 
 	return new;
 }
@@ -1197,7 +1198,8 @@ static struct ctl_table_header *new_links(struct ctl_dir *dir, struct ctl_table_
 		link_name += len;
 		link++;
 	}
-	init_header(links, dir->header.root, dir->header.set, node, link_table);
+	init_header(links, dir->header.root, dir->header.set, node, link_table,
+		    head->ctl_table_size);
 	links->nreg = nr_entries;
 
 	return links;
@@ -1372,7 +1374,7 @@ struct ctl_table_header *__register_sysctl_table(
 		return NULL;
 
 	node = (struct ctl_node *)(header + 1);
-	init_header(header, root, set, node, table);
+	init_header(header, root, set, node, table, nr_entries);
 	if (sysctl_check_table(path, header))
 		goto fail;
 
@@ -1537,7 +1539,7 @@ void setup_sysctl_set(struct ctl_table_set *set,
 {
 	memset(set, 0, sizeof(*set));
 	set->is_seen = is_seen;
-	init_header(&set->dir.header, root, set, NULL, root_table);
+	init_header(&set->dir.header, root, set, NULL, root_table, 1);
 }
 
 void retire_sysctl_set(struct ctl_table_set *set)
-- 
2.30.2

