linux-kernel - [PATCH 1/3] lib/sys_info: handle sys_info

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Message-Id: <20250815071428.98041-2-feng.tang@linux.alibaba.com>
Date: Fri, 15 Aug 2025 15:14:26 +0800
From: Feng Tang <feng.tang@...ux.alibaba.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
	Petr Mladek <pmladek@...e.com>,
	Steven Rostedt <rostedt@...dmis.org>,
	Lance Yang <lance.yang@...ux.dev>,
	Jonathan Corbet <corbet@....net>,
	linux-kernel@...r.kernel.org
Cc: paulmck@...nel.org,
	john.ogness@...utronix.de,
	Feng Tang <feng.tang@...ux.alibaba.com>
Subject: [PATCH 1/3] lib/sys_info: handle sys_info_mask==0 case

It is a normal case that bitmask parameter is 0, so pre-initialize the
names[] to null string to cover this case.

Also remove the superfluous "+1" in names[sizeof(sys_info_avail) + 1],
which is needed for 'strlen()', but not for 'sizeof()'.

Suggested-by: Petr Mladek <pmladek@...e.com>
Signed-off-by: Feng Tang <feng.tang@...ux.alibaba.com>
---
 lib/sys_info.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/lib/sys_info.c b/lib/sys_info.c
index 5bf503fd7ec1..b2df148971ba 100644
--- a/lib/sys_info.c
+++ b/lib/sys_info.c
@@ -55,7 +55,7 @@ int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
 					  void *buffer, size_t *lenp,
 					  loff_t *ppos)
 {
-	char names[sizeof(sys_info_avail) + 1];
+	char names[sizeof(sys_info_avail)];
 	struct ctl_table table;
 	unsigned long *si_bits_global;
 
@@ -81,6 +81,9 @@ int sysctl_sys_info_handler(const struct ctl_table *ro_table, int write,
 		char *delim = "";
 		int i, len = 0;
 
+		/* *si_bits_glabl could be 0 */
+		names[0] = '\0';
+
 		for (i = 0; i < ARRAY_SIZE(si_names); i++) {
 			if (*si_bits_global & si_names[i].bit) {
 				len += scnprintf(names + len, sizeof(names) - len,
-- 
2.43.5