SVG in notifications results in a double free or corruption

[lightdiscord]

When I display a notification with a PNG it works but when it is a SVG no notification is displayed.
In journalctl I have an error:

Apr 30 13:52:22 nixos org.freedesktop.Notifications[1132]: double free or corruption (out)

While the notification gets sent:

signal time=1525089139.442770 sender=org.freedesktop.DBus -> destination=:1.789 serial=2 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameAcquired
   string ":1.789"
signal time=1525089139.442782 sender=org.freedesktop.DBus -> destination=:1.789 serial=4 path=/org/freedesktop/DBus; interface=org.freedesktop.DBus; member=NameLost
   string ":1.789"
method call time=1525089140.924184 sender=:1.790 -> destination=:1.788 serial=6 path=/org/freedesktop/Notifications; interface=org.freedesktop.Notifications; member=GetServerInformation
method call time=1525089140.924710 sender=:1.790 -> destination=:1.788 serial=7 path=/org/freedesktop/Notifications; interface=org.freedesktop.Notifications; member=Notify
   string "notify-send"
   uint32 0
   string "/home/arnaud/Documents/papirus-icons/Papirus/64x64/apps/spotify-client.png"
   string "Hello world!"
   string "this is"
   array [
   ]
   array [
      dict entry(
         string "urgency"
         variant             byte 1
      )
   ]
   int32 -1
method call time=1525089142.006995 sender=:1.791 -> destination=:1.788 serial=6 path=/org/freedesktop/Notifications; interface=org.freedesktop.Notifications; member=GetServerInformation
method call time=1525089142.007305 sender=:1.791 -> destination=:1.788 serial=7 path=/org/freedesktop/Notifications; interface=org.freedesktop.Notifications; member=Notify
   string "notify-send"
   uint32 0
   string "/home/arnaud/Documents/papirus-icons/spotify-client.svg"
   string "Hello world!"
   string "this is"
   array [
   ]
   array [
      dict entry(
         string "urgency"
         variant             byte 1
      )
   ]
   int32 -1

Installation info

• Version: 1.3.1
• Install type: NixOS dunst derivation
• Distro and version: NixOS (18.09pre137749.b5fd3a0bc70 (Jellyfish))

[bebehei]

Just recently, I introduced unit tests in the icon loading methods and found the corresponding bug. In parallel somewhere in the gdk libraries the svg loading broke (?!) or it maybe got more strict. Therefore, gdk fails and dunst crashes.

As the fix is already in #496, I don't consider branching creating a special hotfix.

[bebehei]

As the fix is already in #496, I don't consider branching creating a special hotfix.

Oh wait. Stupid thinking of myself. 🙈

@tsipinakis We actually should create a hotfix and release 1.3.2 to make it available in downstream distros.

[bebehei]

string "/home/arnaud/Documents/papirus-icons/spotify-client.svg"

@lightdiscord Out of curiosity, could you please provide this file?

[lightdiscord]

@lightdiscord Out of curiosity, could you please provide this file?

@bebehei You can find here my local version and here the common one.

[tsipinakis]

I cannot seem to reproduce this with the provided icon. @lightdiscord What version of gdk_pixbuf are you using?

[lightdiscord]

According to this file, i'm using gdk_pixbuf at version 2.36.7

[bebehei]

@tsipinakis A week ago, someone showed up in IRC and asked about a corruption error. The backtrace indicated clearly, that it was the mentioned g_free (instead of g_error_free). I assume, that something somewhere in the GDK libs broke and parses the SVGs more strict and/or fails. And I expect this error here to be the same one as the one in the IRC.

You could search around the changelog on the Gnome FTP Mirror for the corresponding bugreport. But actually, I think this is wasted energy. You could trace it back, but no matter if it's actually a problem of gdk pixbuf, dunst doesn't behave right either.

I think we should fix dunst first.

For completeness: With the given file, I can't reproduce it either. But as I said, I'm expecting the bug in the libraries (gdk-pixbuf2 2.36.12). The most effective job to find the actual issue would be bisecting the libs. But that's too much effort.

---

@lightdiscord Could you please compile the refactor-drawing branch manually and run it on your system and trigger the bad notification?

git clone https://github.com/dunst-project/dunst.git
cd dunst
git checkout refactor-drawing
make
killall dunst
./dunst -print
# -> trigger the notification

[tsipinakis]

I think we should fix dunst first.

The fix is already in refactor-drawing and will land in master (hopefully soon) I'm still thinking it over if it's worth doing another patch release for this one.

In any case, I also expect this to be a bug somewhere in gdk but it's worth looking into IMO (at least finding out the error message it gives out when it fails)

[bebehei]

Yes, I also think we should do a patch release. Getting a meaningful error message afterwards and then fixing it upstream is also in my mind.

[lightdiscord]

With the refactor-drawing branch dunst doesn't crash with a svg icon, but the icon isn't displayed.

[tsipinakis]

Check the logs, there should be an error message on why it failed to load.

[lightdiscord]

Check the logs

I can't find them

[tsipinakis]

I can't find them

Huh, try the following

git pull --force (make sure you have the latest commits I pushed earlier)

make clean
make debug (enable all debug output)
strace ./dunst > log 2>&1  (run under strace to see what's going on under the hood and put everything in log)
#send notifications through

And post the log this should hopefully give enough information to figure this out.

Edit: Relevant code bit is here

dunst/src/icon.c

Lines 63 to 71 in 534b09c

	if (is_readable_file(filename)) {
	GError *error = NULL;
	pixbuf = gdk_pixbuf_new_from_file(filename, &error);
	if (!pixbuf) {
	LOG_M("%s", error->message);
	g_error_free(error);
	}
	}
	return pixbuf;

The only condition in which it doesn't print an error is if it can't read the file for some reason which is what I'm suspecting currently (but then again it wouldn't crash without the patch?).

[lightdiscord]

So many lines in logs.txt

I send a notification with the png then with the svg