Bug 1285604 - gdk-pixbuf loaders can cause SEGV in nautilus
Summary: gdk-pixbuf loaders can cause SEGV in nautilus
Keywords:
Status: CLOSED EOL
Alias: None
Product: Fedora
Classification: Fedora
Component: gdk-pixbuf2
Version: 24
Hardware: Unspecified
OS: Unspecified
unspecified
unspecified
Target Milestone: ---
Assignee: Matthias Clasen
QA Contact: Fedora Extras Quality Assurance
URL:
Whiteboard:
Depends On:
Blocks: 1279152
TreeView+ depends on / blocked
 
Reported: 2015-11-26 02:34 UTC by Yaakov Selkowitz
Modified: 2017-08-08 12:27 UTC (History)
1 user (show)

Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Clone Of: 1279152
Environment:
Last Closed: 2017-08-08 12:27:47 UTC
Type: Bug
Embargoed:


Attachments (Terms of Use)

Description Yaakov Selkowitz 2015-11-26 02:34:39 UTC
+++ This bug was initially created as a clone of Bug #1279152 +++

Version-Release number of selected component (if applicable):
libopenraw-pixbuf-loader-0.0.9-10.fc22.x86_64
gdk-pixbuf2-2.31.6-1.fc22.x86_64

How reproducible:
100%

Steps to Reproduce:
1. install libopenraw-pixbuf-loader
2. download (into e.g. ~/Downloads) a RAW file not supported by libopenraw, e.g. http://www.rawsamples.ch/raws/olympus/sp350/RAW_OLYMPUS_SP350.ORF
3. start/open nautilus
4. in Preferences->Preview, make sure "Show thumbnails" is not "Never" and "Only for files smaller than" is set to at least 100MB (the above example is ~12MB)
5. then browse to the folder (e.g. ~/Downloads) containing the RAW file.

Actual results:
Segfault.

Expected results:
Error message to stderr, no thumbnail generated.

Description of problem:
gdk_pixbuf_loader_close is documented to set a non-NULL @error when returning FALSE, but lines 821-831 allow the possibility of returning FALSE without setting @error:

https://git.gnome.org/browse/gdk-pixbuf/tree/gdk-pixbuf/gdk-pixbuf-loader.c?h=gdk-pixbuf-2-32#n766

libgnome-desktop's _gdk_pixbuf_new_from_uri_at_scale (used by Nautilus to generate thumbnails for image formats supported by GdkPixbuf) depends on the documented behaviour by accessing error->message without checking that error != NULL:

https://git.gnome.org/browse/gnome-desktop/tree/libgnome-desktop/gnome-desktop-thumbnail.c?h=gnome-3-18#n552

However, libopenraw's gdk_pixbuf__or_image_stop_load, which is the vfunc called by gdk_pixbuf_loader_close, completely ignores @error:

http://cgit.freedesktop.org/libopenraw/tree/gnome/pixbuf-loader.c#n93

So, when faced with a RAW image that libopenraw does not support (which, at least in 0.0.9 are many, given that there are four years of yet unreleased development in upstream git), libopenraw-pixbuf-loader causes gdk_pixbuf_loader_close to return FALSE but does *not* set @error as promised.  The result is a NULL dereference in libgnome-desktop causing nautilus to SEGV.

Ultimately, there is plenty of blame to go around here:

* libopenraw-0.0.9 does not support many currently available RAW formats.  The possibility of shipping a git snapshot, or even better getting upstream to ship a new release, would make this library much more useful.  I have not investigated the API/ABI compatibility of git master vs. 0.0.9.

* Regardless, libopenraw's gdk_pixbuf__or_image_stop_load should conform with the documented requirement of gdk_pixbuf_loader_close (see bug 1279152)
  
* gdk_pixbuf_loader_close must conform with its documentation and assure that (a non-NULL) @error is always set when returning FALSE, in case a(nother) loader's stop_load vfunc does not conform.

* it could be argued that libgnome-desktop should check for error != NULL before error->message, but OTOH gdk-pixbuf's documentation does indicate that it is a safe assumption to make.

I believe this affects all supported versions of Fedora.

Comment 1 Jan Kurik 2016-02-24 14:01:53 UTC
This bug appears to have been reported against 'rawhide' during the Fedora 24 development cycle.
Changing version to '24'.

More information and reason for this action is here:
https://fedoraproject.org/wiki/Fedora_Program_Management/HouseKeeping/Fedora24#Rawhide_Rebase

Comment 2 Fedora End Of Life 2017-07-25 19:33:53 UTC
This message is a reminder that Fedora 24 is nearing its end of life.
Approximately 2 (two) weeks from now Fedora will stop maintaining
and issuing updates for Fedora 24. It is Fedora's policy to close all
bug reports from releases that are no longer maintained. At that time
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Comment 3 Fedora End Of Life 2017-08-08 12:27:47 UTC
Fedora 24 changed to end-of-life (EOL) status on 2017-08-08. Fedora 24 is
no longer maintained, which means that it will not receive any further
security or bug fix updates. As a result we are closing this bug.

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