+ lib-sys_info-handle-sys_info_mask==0-case.patch added to mm-nonmm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: lib/sys_info: handle sys_info_mask==0 case
has been added to the -mm mm-nonmm-unstable branch.  Its filename is
     lib-sys_info-handle-sys_info_mask==0-case.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/lib-sys_info-handle-sys_info_mask==0-case.patch

This patch will later appear in the mm-nonmm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Feng Tang <feng.tang@linux.alibaba.com>
Subject: lib/sys_info: handle sys_info_mask==0 case
Date: Fri, 15 Aug 2025 15:14:26 +0800

Patch series "follow up patches for panic_print's generalization".

Generalization of panic_print's dump function has been merged [1], and
this patchset is to address some remaining issues, like adding note of the
obsoletion of 'panic_print' cmdline parameter, refining the kernel
document for panic_print, and hardening some string management.


This patch (of 3):

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()'.

Link: https://lkml.kernel.org/r/20250815071428.98041-1-feng.tang@linux.alibaba.com
Link: https://lkml.kernel.org/r/20250815071428.98041-2-feng.tang@linux.alibaba.com
Link: https://lkml.kernel.org/r/20250703021004.42328-1-feng.tang@linux.alibaba.com [1]
Signed-off-by: Feng Tang <feng.tang@linux.alibaba.com>
Suggested-by: Petr Mladek <pmladek@suse.com>
Cc: John Ogness <john.ogness@linutronix.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: "Paul E . McKenney" <paulmck@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Askar Safin <safinaskar@zohomail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 lib/sys_info.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/lib/sys_info.c~lib-sys_info-handle-sys_info_mask==0-case
+++ a/lib/sys_info.c
@@ -55,7 +55,7 @@ int sysctl_sys_info_handler(const struct
 					  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
 		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,
_

Patches currently in -mm which might be from feng.tang@linux.alibaba.com are

lib-sys_info-handle-sys_info_mask==0-case.patch
panic-refine-the-document-for-panic_print.patch
panic-add-note-that-panic_print-parameter-is-deprecated.patch