[PATCH 14/14] sysctl: Use size as stopping criteria for list macro

From: Joel Granados
Date: Wed Jul 26 2023 - 10:09:00 EST


Add header->ctl_table_size as an additional stopping criteria for the
list_for_each_table_entry macro. In this way it will execute until it
finds an "empty" ->procname or until the size runs out. Therefore if a
ctl_table array with a sentinel is passed its size will be too big (by
one element) but it will stop on the sentinel. On the other hand, if the
ctl_table array without a sentinel is passed its size will be just write
and there will be no need for a sentinel.

Signed-off-by: Joel Granados <j.granados@xxxxxxxxxxx>
---
fs/proc/proc_sysctl.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c
index 6c0721cd35f3..3eea34d98d54 100644
--- a/fs/proc/proc_sysctl.c
+++ b/fs/proc/proc_sysctl.c
@@ -19,8 +19,9 @@
#include <linux/kmemleak.h>
#include "internal.h"

-#define list_for_each_table_entry(entry, header) \
- for ((entry) = (header->ctl_table); (entry)->procname; (entry)++)
+#define list_for_each_table_entry(entry, header) \
+ entry = header->ctl_table; \
+ for (size_t i = 0 ; i < header->ctl_table_size && entry->procname; ++i, entry++)

static const struct dentry_operations proc_sys_dentry_operations;
static const struct file_operations proc_sys_file_operations;
--
2.30.2