From aef43552fc213111ae8967195ac382e1f9d083e2 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 19 Sep 2023 16:03:27 +0200
Subject: [PATCH 1/3] cgroup-util: rename return param to 'ret', as per coding
 style

---
 src/basic/cgroup-util.c | 33 ++++++++++++++++-----------------
 src/basic/cgroup-util.h | 11 +++++------
 2 files changed, 21 insertions(+), 23 deletions(-)

diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index b2b0ddd190..6e6d075392 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -39,12 +39,12 @@
 #include "user-util.h"
 #include "xattr-util.h"
 
-static int cg_enumerate_items(const char *controller, const char *path, FILE **_f, const char *item) {
+static int cg_enumerate_items(const char *controller, const char *path, FILE **ret, const char *item) {
         _cleanup_free_ char *fs = NULL;
         FILE *f;
         int r;
 
-        assert(_f);
+        assert(ret);
 
         r = cg_get_path(controller, path, item, &fs);
         if (r < 0)
@@ -54,22 +54,21 @@ static int cg_enumerate_items(const char *controller, const char *path, FILE **_
         if (!f)
                 return -errno;
 
-        *_f = f;
+        *ret = f;
         return 0;
 }
 
-int cg_enumerate_processes(const char *controller, const char *path, FILE **_f) {
-        return cg_enumerate_items(controller, path, _f, "cgroup.procs");
+int cg_enumerate_processes(const char *controller, const char *path, FILE **ret) {
+        return cg_enumerate_items(controller, path, ret, "cgroup.procs");
 }
 
-int cg_read_pid(FILE *f, pid_t *_pid) {
+int cg_read_pid(FILE *f, pid_t *ret) {
         unsigned long ul;
 
-        /* Note that the cgroup.procs might contain duplicates! See
-         * cgroups.txt for details. */
+        /* Note that the cgroup.procs might contain duplicates! See cgroups.txt for details. */
 
         assert(f);
-        assert(_pid);
+        assert(ret);
 
         errno = 0;
         if (fscanf(f, "%lu", &ul) != 1) {
@@ -83,7 +82,7 @@ int cg_read_pid(FILE *f, pid_t *_pid) {
         if (ul <= 0)
                 return -EIO;
 
-        *_pid = (pid_t) ul;
+        *ret = (pid_t) ul;
         return 1;
 }
 
@@ -178,12 +177,12 @@ bool cg_kill_supported(void) {
         return supported;
 }
 
-int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
+int cg_enumerate_subgroups(const char *controller, const char *path, DIR **ret) {
         _cleanup_free_ char *fs = NULL;
-        int r;
         DIR *d;
+        int r;
 
-        assert(_d);
+        assert(ret);
 
         /* This is not recursive! */
 
@@ -195,13 +194,13 @@ int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
         if (!d)
                 return -errno;
 
-        *_d = d;
+        *ret = d;
         return 0;
 }
 
-int cg_read_subgroup(DIR *d, char **fn) {
+int cg_read_subgroup(DIR *d, char **ret) {
         assert(d);
-        assert(fn);
+        assert(ret);
 
         FOREACH_DIRENT_ALL(de, d, return -errno) {
                 char *b;
@@ -216,7 +215,7 @@ int cg_read_subgroup(DIR *d, char **fn) {
                 if (!b)
                         return -ENOMEM;
 
-                *fn = b;
+                *ret = b;
                 return 1;
         }
 
diff --git a/src/basic/cgroup-util.h b/src/basic/cgroup-util.h
index 9b30ae0396..6e7845345a 100644
--- a/src/basic/cgroup-util.h
+++ b/src/basic/cgroup-util.h
@@ -176,13 +176,12 @@ typedef enum CGroupUnified {
  * generate paths with multiple adjacent / removed.
  */
 
-int cg_enumerate_processes(const char *controller, const char *path, FILE **_f);
-int cg_read_pid(FILE *f, pid_t *_pid);
-int cg_read_event(const char *controller, const char *path, const char *event,
-                  char **val);
+int cg_enumerate_processes(const char *controller, const char *path, FILE **ret);
+int cg_read_pid(FILE *f, pid_t *ret);
+int cg_read_event(const char *controller, const char *path, const char *event, char **ret);
 
-int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d);
-int cg_read_subgroup(DIR *d, char **fn);
+int cg_enumerate_subgroups(const char *controller, const char *path, DIR **ret);
+int cg_read_subgroup(DIR *d, char **ret);
 
 typedef enum CGroupFlags {
         CGROUP_SIGCONT     = 1 << 0,

From 8ab40789d93947b2be963fe72993eae642ccaeec Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 19 Sep 2023 16:03:56 +0200
Subject: [PATCH 2/3] cgroup-util: initialize return param on all success
 returns

As per coding style.
---
 src/basic/cgroup-util.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 6e6d075392..2d13e48366 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -73,8 +73,10 @@ int cg_read_pid(FILE *f, pid_t *ret) {
         errno = 0;
         if (fscanf(f, "%lu", &ul) != 1) {
 
-                if (feof(f))
+                if (feof(f)) {
+                        *ret = 0;
                         return 0;
+                }
 
                 return errno_or_else(EIO);
         }
@@ -219,6 +221,7 @@ int cg_read_subgroup(DIR *d, char **ret) {
                 return 1;
         }
 
+        *ret = NULL;
         return 0;
 }
 

From 5ed7cdfb8fcaf1074174680e404dab5c366dba85 Mon Sep 17 00:00:00 2001
From: Lennart Poettering <lennart@poettering.net>
Date: Tue, 19 Sep 2023 16:04:34 +0200
Subject: [PATCH 3/3] cgroup-util: tighten range check before casting to pid_t

---
 src/basic/cgroup-util.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/src/basic/cgroup-util.c b/src/basic/cgroup-util.c
index 2d13e48366..92caccfcd4 100644
--- a/src/basic/cgroup-util.c
+++ b/src/basic/cgroup-util.c
@@ -83,6 +83,8 @@ int cg_read_pid(FILE *f, pid_t *ret) {
 
         if (ul <= 0)
                 return -EIO;
+        if (ul > PID_T_MAX)
+                return -EIO;
 
         *ret = (pid_t) ul;
         return 1;