Bug 520901

Summary: Slideshow freezes and stops responding when encountering JPEG with 0xDEADBEEF marker in EXIF UserComment field
Product: [Applications] digikam Reporter: Matthias <hallomatthias>
Component: Plugin-Generic-SlideShowAssignee: Digikam Developers <digikam-bugs-null>
Status: RESOLVED FIXED    
Severity: crash CC: caulier.gilles, metzpinguin
Priority: NOR    
Version First Reported In: 9.0.0   
Target Milestone: ---   
Platform: Microsoft Windows   
OS: Microsoft Windows   
Latest Commit: https://invent.kde.org/graphics/digikam/-/commit/0284120183a30a460d986a0d982606685d78b5f9 Version Fixed/Implemented In: 9.1.0
Sentry Crash Report:

Description Matthias 2026-06-01 09:51:15 UTC 
Slideshow crashes when displaying JPEG images with 0xDEADBEEF 
marker in EXIF UserComment field (Samsung GT-I9505 smartphone photos).

Steps to reproduce:
1. Create a slideshow containing at least one JPEG with a 
   0xDEADBEEF marker in the EXIF UserComment field. 
2. Start and process the slideshow
3. Wait until the slideshow tries to load the affected image

Observed result:
The slideshow freezes on the image preceding the affected one 
and digiKam stops responding entirely.

Expected result:
Slideshow displays all images without crashing

Root cause identified:
Affected JPEGs contain EXIF UserComment field with 0xDEADBEEF 
debug marker written by Samsung firmware (I9505XXUENA1).
Removing the description field in digiKAM fixes the crash.

System:
- digiKam 9.0.0 / Qt 6.9.1 / KDE Frameworks 6.17.0
- Windows 11 25H2
- NVIDIA GeForce GPU
Comment 1 caulier.gilles 2026-06-01 10:06:15 UTC 
It's probably a problem with Exiv2.

Try to switch to ExifTool metadata backend.

Try also the 9.1.0 pre-release (will be published next week end) where Exiv2 have been updated (compared to 9.0.0)

Please share the problematic JPEG file.

Best regards

Gilles Caulier
Comment 2 Matthias 2026-06-01 12:42:54 UTC 
Sorry Gilles, I do not have the problematic JPEG file anymore :-(
I fixed it by deleting the content of the description field in digiKAM. Before deleting, there was some binary content included in this field, starting with "METADATA..."
Comment 3 Maik Qualmann 2026-06-01 17:57:25 UTC 
Hmm, that's a bit tricky without a sample image. The marker 0xDEADBEEF stands for "dead beef"—just give it a quick Google search.
I actually still have a Galaxy S4 (model I9506) right here. It doesn't write anything to the Exif User Comment field. The differences between the *5 and *6 models lie in the processor and the LTE standard.

Maik
Comment 4 Maik Qualmann 2026-06-01 18:06:36 UTC 
Okay, but I also see a long string of binary text as a caption on my S4 image; I'll take a look at it.

Maik
Comment 5 Maik Qualmann 2026-06-01 18:20:00 UTC 
Git commit 059c20c6165a3cda00bda2c349ba6031f3345421 by Maik Qualmann.
Committed on 01/06/2026 at 18:19.
Pushed by mqualmann into branch 'master'.

fix find end of ASCII user comment

M  +4    -2    core/libs/metadataengine/engine/metaengine_p.cpp

https://invent.kde.org/graphics/digikam/-/commit/059c20c6165a3cda00bda2c349ba6031f3345421
Comment 6 Maik Qualmann 2026-06-01 19:25:56 UTC 
Git commit 0284120183a30a460d986a0d982606685d78b5f9 by Maik Qualmann.
Committed on 01/06/2026 at 19:24.
Pushed by mqualmann into branch 'master'.

fix endless loop in caption print and check ASCII value
FIXED-IN: 9.1.0

M  +1    -1    NEWS
M  +5    -1    core/libs/metadataengine/engine/metaengine_p.cpp
M  +7    -0    core/libs/threadimageio/preview/previewosdsettings.cpp

https://invent.kde.org/graphics/digikam/-/commit/0284120183a30a460d986a0d982606685d78b5f9