From d6e771a1936f54ff1693d84625de57b199bd6c6f Mon Sep 17 00:00:00 2001

From: Martin Pitt <martin.pitt@ubuntu.com>

Date: Mon, 1 Jun 2015 11:32:39 +0200

Subject: [PATCH] sd-device: fix invalid property strv pointers

In device_update_properties_bufs(), the strv is built from pointers into the

single nul-terminated buf_nulstr string, to avoid allocating the key=value

strings twice. However, we must not do that while building and

GREEDY_REALLOC0()'ing buf_nulstr, as each time when this actually reallocates

memory the pointers we wrote into buf_strv so far become invalid.

So change the logic to first completely build the new buf_nulstr, and then

iterate over it to pick out the pointers to the individual key=value strings

for properties_strv.

This fixes invalid environment for udev callouts.

(cherry picked from commit d854ba50a82f28b776c670d27156f0e9881fde8a)

---

 src/libsystemd/sd-device/device-private.c | 23 +++++++++++++----------

 1 file changed, 13 insertions(+), 10 deletions(-)

diff --git a/src/libsystemd/sd-device/device-private.c b/src/libsystemd/sd-device/device-private.c

index 10370af029..deb8efd05d 100644

--- a/src/libsystemd/sd-device/device-private.c

+++ b/src/libsystemd/sd-device/device-private.c

@@ -636,10 +636,9 @@ int device_new_from_nulstr(sd_device **ret, uint8_t *nulstr, size_t len) {

 static int device_update_properties_bufs(sd_device *device) {

         const char *val, *prop;

-        char **buf_strv = NULL;

         uint8_t *buf_nulstr = NULL;

-        size_t allocated_nulstr = 0, allocated_strv = 0;

-        size_t nulstr_len = 0, strv_size = 0;

+        size_t allocated_nulstr = 0;

+        size_t nulstr_len = 0, num = 0, i;

         assert(device);

@@ -655,20 +654,24 @@ static int device_update_properties_bufs(sd_device *device) {

                 if (!buf_nulstr)

                         return -ENOMEM;

-                buf_strv = GREEDY_REALLOC0(buf_strv, allocated_strv, strv_size + 2);

-                if (!buf_strv)

-                        return -ENOMEM;

-

-                buf_strv[strv_size ++] = (char *)&buf_nulstr[nulstr_len];

                 strscpyl((char *)buf_nulstr + nulstr_len, len + 1, prop, "=", val, NULL);

                 nulstr_len += len + 1;

+                ++num;

         }

         free(device->properties_nulstr);

-        free(device->properties_strv);

         device->properties_nulstr = buf_nulstr;

         device->properties_nulstr_len = nulstr_len;

-        device->properties_strv = buf_strv;

+

+        /* build strv from buf_nulstr */

+        free(device->properties_strv);

+        device->properties_strv = new0(char *, num + 1);

+        i = 0;

+        NULSTR_FOREACH(val, (char*) buf_nulstr) {

+                device->properties_strv[i] = (char *) val;

+                assert(i < num);

+                i++;

+        }

         device->properties_buf_outdated = false;