+ tools-mm-page_owner_sort-bound-pattern-output-copies.patch added to mm-new branch

+ tools-mm-page_owner_sort-bound-pattern-output-copies.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: tools/mm/page_owner_sort: bound pattern output copies
has been added to the -mm mm-new branch.  Its filename is
     tools-mm-page_owner_sort-bound-pattern-output-copies.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/tools-mm-page_owner_sort-bound-pattern-output-copies.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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and is updated there most days

------------------------------------------------------
From: Yichong Chen <chenyichong@uniontech.com>
Subject: tools/mm/page_owner_sort: bound pattern output copies
Date: Mon, 29 Jun 2026 09:43:16 +0800

search_pattern() copies a regex capture into caller-provided buffers
without knowing their sizes.  Several callers pass fixed-size buffers,
including FIELD_BUFF and TASK_COMM_LEN.

Pass the destination size to search_pattern(), reject captures that do not
fit before copying them, and terminate the output string inside
search_pattern().

Link: https://lore.kernel.org/20260629014316.130307-4-chenyichong@uniontech.com
Signed-off-by: Yichong Chen <chenyichong@uniontech.com>
Cc: Vishal Moola <vishal.moola@gmail.com>
Cc: Ye Liu <ye.liu@linux.dev>
Cc: Zhen Ni <zhen.ni@easystack.cn>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/mm/page_owner_sort.c |   27 +++++++++++++++++++++------
 1 file changed, 21 insertions(+), 6 deletions(-)

--- a/tools/mm/page_owner_sort.c~tools-mm-page_owner_sort-bound-pattern-output-copies
+++ a/tools/mm/page_owner_sort.c
@@ -237,7 +237,8 @@ static int remove_pattern(regex_t *patte
 	return len - (pmatch[1].rm_eo - pmatch[1].rm_so);
 }
 
-static int search_pattern(regex_t *pattern, char *pattern_str, char *buf)
+static int search_pattern(regex_t *pattern, char *pattern_str,
+			  size_t pattern_str_size, char *buf)
 {
 	int err, val_len;
 	regmatch_t pmatch[2];
@@ -249,8 +250,14 @@ static int search_pattern(regex_t *patte
 		return -1;
 	}
 	val_len = pmatch[1].rm_eo - pmatch[1].rm_so;
+	if ((size_t)val_len >= pattern_str_size) {
+		if (debug_on)
+			fprintf(stderr, "pattern too long in %s\n", buf);
+		return -1;
+	}
 
 	memcpy(pattern_str, buf + pmatch[1].rm_so, val_len);
+	pattern_str[val_len] = '\0';
 
 	return 0;
 }
@@ -307,7 +314,8 @@ static int get_page_num(char *buf)
 	char order_str[FIELD_BUFF] = {0};
 	char *endptr;
 
-	search_pattern(&order_pattern, order_str, buf);
+	if (search_pattern(&order_pattern, order_str, sizeof(order_str), buf) < 0)
+		return 0;
 	errno = 0;
 	order_val = strtol(order_str, &endptr, 10);
 	if (order_val > 64 || errno != 0 || endptr == order_str || *endptr != '\0') {
@@ -325,7 +333,8 @@ static pid_t get_pid(char *buf)
 	char pid_str[FIELD_BUFF] = {0};
 	char *endptr;
 
-	search_pattern(&pid_pattern, pid_str, buf);
+	if (search_pattern(&pid_pattern, pid_str, sizeof(pid_str), buf) < 0)
+		return -1;
 	errno = 0;
 	pid = strtol(pid_str, &endptr, 10);
 	if (errno != 0 || endptr == pid_str || *endptr != '\0') {
@@ -344,7 +353,8 @@ static pid_t get_tgid(char *buf)
 	char tgid_str[FIELD_BUFF] = {0};
 	char *endptr;
 
-	search_pattern(&tgid_pattern, tgid_str, buf);
+	if (search_pattern(&tgid_pattern, tgid_str, sizeof(tgid_str), buf) < 0)
+		return -1;
 	errno = 0;
 	tgid = strtol(tgid_str, &endptr, 10);
 	if (errno != 0 || endptr == tgid_str || *endptr != '\0') {
@@ -363,7 +373,9 @@ static __u64 get_ts_nsec(char *buf)
 	char ts_nsec_str[FIELD_BUFF] = {0};
 	char *endptr;
 
-	search_pattern(&ts_nsec_pattern, ts_nsec_str, buf);
+	if (search_pattern(&ts_nsec_pattern, ts_nsec_str,
+			   sizeof(ts_nsec_str), buf) < 0)
+		return -1;
 	errno = 0;
 	ts_nsec = strtoull(ts_nsec_str, &endptr, 10);
 	if (errno != 0 || endptr == ts_nsec_str || *endptr != '\0') {
@@ -384,7 +396,10 @@ static char *get_comm(char *buf)
 
 	memset(comm_str, 0, TASK_COMM_LEN);
 
-	search_pattern(&comm_pattern, comm_str, buf);
+	if (search_pattern(&comm_pattern, comm_str, TASK_COMM_LEN, buf) < 0) {
+		free(comm_str);
+		return NULL;
+	}
 	errno = 0;
 	if (errno != 0) {
 		if (debug_on)
_

Patches currently in -mm which might be from chenyichong@uniontech.com are

tools-mm-page_owner_sort-return-explicit-filter-results.patch
tools-mm-page_owner_sort-free-per-record-allocations.patch
tools-mm-page_owner_sort-bound-pattern-output-copies.patch