From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Mon, 12 Dec 2022 05:16:09 +0000 (+0900)
Subject: sd-device: fix double-free
X-Git-Tag: v253-rc1~319^2~1
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=eb18e7b7825e8320bb4d6269690ef8c3f5461d2b;p=thirdparty%2Fsystemd.git

sd-device: fix double-free

If an attribute is read but the value is not used (i.e. ret_value is NULL),
then sd_device_get_sysattr_value() mistakenly frees the read data even though
it is cached internally.

Fixes a bug introduced by acfc2a1d15560084e077ffb3be472cd117e9020a.

Fixes #25702.
---

diff --git a/src/libsystemd/sd-device/sd-device.c b/src/libsystemd/sd-device/sd-device.c
index 55a0ee730e8..9c4743f0550 100644
--- a/src/libsystemd/sd-device/sd-device.c
+++ b/src/libsystemd/sd-device/sd-device.c
@@ -2332,9 +2332,14 @@ _public_ int sd_device_get_sysattr_value(sd_device *device, const char *sysattr,
                                        sysattr, value, ret_value ? "" : ", ignoring");
                 if (ret_value)
                         return r;
-        } else if (ret_value)
-                *ret_value = TAKE_PTR(value);
 
+                return 0;
+        }
+
+        if (ret_value)
+                *ret_value = value;
+
+        TAKE_PTR(value);
         return 0;
 }