From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Tue, 10 May 2022 14:05:04 +0000 (+0900)
Subject: sd-device: always translate sysname to sysfs filename
X-Git-Tag: v251-rc3~4^2~1
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=4d38294baf31ac193f4897dccb2645b86f1c390f;p=thirdparty%2Fsystemd.git

sd-device: always translate sysname to sysfs filename

Previously, in sd_device_new_from_subsystem_sysname(), '/' in sysname
was replaced '!' for several limited subsystems. This was based on a wrong
assumption that no sysname in e.g. driver subsystem does not contain '!'.
And the assumption is actually wrong, and trigger issue #23327.

In device_set_sysname_and_sysnum() we unconditionally replace '!' in the
filename. Hence, the translation in sd_device_new_from_subsystem_sysname()
must be also done unconditionally.

Fixes #23327.
---

diff --git a/src/libsystemd/sd-device/sd-device.c b/src/libsystemd/sd-device/sd-device.c
index 0bfcdcdf2d9..aaf951ced89 100644
--- a/src/libsystemd/sd-device/sd-device.c
+++ b/src/libsystemd/sd-device/sd-device.c
@@ -414,17 +414,21 @@ _public_ int sd_device_new_from_subsystem_sysname(
         assert_return(path_is_normalized(subsystem), -EINVAL);
         assert_return(path_is_normalized(sysname), -EINVAL);
 
+        /* translate sysname back to sysfs filename */
+        name = strdupa_safe(sysname);
+        string_replace_char(name, '/', '!');
+
         if (streq(subsystem, "subsystem")) {
                 FOREACH_STRING(s, "/sys/bus/", "/sys/class/") {
-                        r = device_strjoin_new(s, sysname, NULL, NULL, ret);
+                        r = device_strjoin_new(s, name, NULL, NULL, ret);
                         if (r < 0)
                                 return r;
                         if (r > 0)
                                 return 0;
                 }
 
-        } else  if (streq(subsystem, "module")) {
-                r = device_strjoin_new("/sys/module/", sysname, NULL, NULL, ret);
+        } else if (streq(subsystem, "module")) {
+                r = device_strjoin_new("/sys/module/", name, NULL, NULL, ret);
                 if (r < 0)
                         return r;
                 if (r > 0)
@@ -433,10 +437,10 @@ _public_ int sd_device_new_from_subsystem_sysname(
         } else if (streq(subsystem, "drivers")) {
                 const char *sep;
 
-                sep = strchr(sysname, ':');
+                sep = strchr(name, ':');
                 if (sep && sep[1] != '\0') { /* Require ":" and something non-empty after that. */
 
-                        const char *subsys = memdupa_suffix0(sysname, sep - sysname);
+                        const char *subsys = memdupa_suffix0(name, sep - name);
                         sep++;
 
                         if (streq(sep, "drivers")) /* If the sysname is "drivers", then it's the drivers directory itself that is meant. */
@@ -450,12 +454,6 @@ _public_ int sd_device_new_from_subsystem_sysname(
                 }
         }
 
-        /* translate sysname back to sysfs filename */
-        name = strdupa_safe(sysname);
-        for (size_t i = 0; name[i]; i++)
-                if (name[i] == '/')
-                        name[i] = '!';
-
         r = device_strjoin_new("/sys/bus/", subsystem, "/devices/", name, ret);
         if (r < 0)
                 return r;
@@ -468,7 +466,7 @@ _public_ int sd_device_new_from_subsystem_sysname(
         if (r > 0)
                 return 0;
 
-        r = device_strjoin_new("/sys/firmware/", subsystem, "/", sysname, ret);
+        r = device_strjoin_new("/sys/firmware/", subsystem, "/", name, ret);
         if (r < 0)
                 return r;
         if (r > 0)