Bug 754887 – Loading a binary file cause a crash

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Bug 754887 - Loading a binary file cause a crash


Summary:	Loading a binary file cause a crash


Status:	RESOLVED DUPLICATE of bug 738504

Product:	gtksourceview
Classification:	Platform
Component:	File loading and saving
Version:	3.17.x
Hardware:	Other Linux

Importance:	Normal minor
Target Milestone:	---
Assigned To:	GTK Sourceview maintainers
QA Contact:	GTK Sourceview maintainers

URL:
Whiteboard:

Depends on:
Blocks:

Reported:	2015-09-11 15:25 UTC by Mantas Mikulėnas (grawity)
Modified:	2015-09-12 09:42 UTC

See Also:
GNOME target:	---
GNOME version:	---

Attachments
example file (2.80 KB, application/octet-stream) 2015-09-11 15:25 UTC, Mantas Mikulėnas (grawity)	Details

Description Mantas Mikulėnas (grawity) 2015-09-11 15:25:20 UTC

Created attachment 311156 [details]
example file

Some programs crash when trying to display non-UTF-8 files (mainly, binary files):

> Gtk:ERROR:gtktextsegment.c:195:_gtk_char_segment_new: assertion failed: (gtk_text_byte_begins_utf8_char (text))
> Aborted (core dumped)

This affects gEdit and more importantly gnome-terminal (where it's not uncommon to accidentally `cat` a binary file).

gtk3 3.17.8.r116.g4993b02 (git master)

Comment 1 Emmanuele Bassi (:ebassi) 2015-09-11 15:34:40 UTC

The crash is inside GtkCharSegment, which is used by the GtkTextBTree, i.e. GtkTextBuffer — something that is not used by gnome-terminal, so it has no bearing on any gnome-terminal crash.

GtkTextView is a GTK+ widget, and as such it has to receive UTF-8 text only. It's up to the caller to ensure that the text is UTF-8, as adding UTF-8 validation to all text-related API would be excessively expensive.

If gedit is crashing because of an invalid UTF-8 file, then the issue lies in gedit and/or GtkSourceView.

Re-assigning to the right component.

Comment 2 Sébastien Wilmet 2015-09-11 16:06:16 UTC

g_utf8_validate() is called in gtk_text_buffer_emit_insert() and returns TRUE.
But later, gtk_text_byte_begins_utf8_char() returns FALSE.

Anyway, opening binary files with GtkSourceFileLoader (and thus gedit) is known to be buggy. Re-assigning to GtkSourceView.

The backtrace:

+ Trace 235435

#0 raise
from /lib64/libc.so.6
#1 abort
from /lib64/libc.so.6
#2 g_assertion_message
#3 g_assertion_message_expr
#4 _gtk_char_segment_new
at gtktextsegment.c line 195
#5 _gtk_text_btree_insert
at gtktextbtree.c line 1182
#6 gtk_text_buffer_real_insert_text
at gtktextbuffer.c line 894
#7 gtk_source_buffer_real_insert_text
at gtksourcebuffer.c line 1052
#8 _gtk_marshal_VOID__BOXED_STRING_INT
at gtkmarshalers.c line 3255
#9 g_type_class_meta_marshal
at gclosure.c line 994
#10 g_closure_invoke
at gclosure.c line 801
#11 signal_emit_unlocked_R
at gsignal.c line 3654
#12 g_signal_emit_valist
at gsignal.c line 3372
#13 g_signal_emit
at gsignal.c line 3428
#14 gtk_text_buffer_emit_insert
at gtktextbuffer.c line 917
#15 gtk_text_buffer_insert
at gtktextbuffer.c line 948
#16 validate_and_insert
at gtksourcebufferoutputstream.c line 680
#17 gtk_source_buffer_output_stream_write
at gtksourcebufferoutputstream.c line 1046
#18 g_output_stream_write
at goutputstream.c line 219
#19 write_file_chunk
at gtksourcefileloader.c line 516
#20 read_cb
at gtksourcefileloader.c line 621
#21 async_ready_callback_wrapper
at ginputstream.c line 529
#22 g_task_return_now
at gtask.c line 1104
#23 complete_in_idle_cb
at gtask.c line 1118
#24 g_idle_dispatch
at gmain.c line 5441
#25 g_main_dispatch
at gmain.c line 3154
#26 g_main_context_dispatch
at gmain.c line 3769
#27 g_main_context_iterate
at gmain.c line 3840
#28 g_main_context_iteration
at gmain.c line 3901
#29 g_application_run
at gapplication.c line 2311
#30 main
at gedit/gedit.c line 146

Comment 3 Mantas Mikulėnas (grawity) 2015-09-11 18:01:26 UTC

Seems like GtkSourceView is fine – bisected down to 3188b8e in glib:

commit 3188b8ee791a38ac3dd7e477f30761344442f745
Author: Mikhail Zabaluev <mikhail.zabaluev@gmail.com>
Date:   Tue Oct 14 01:18:57 2014 +0300

    Optimized branching in g_utf8_validate()

Comment 4 Sébastien Wilmet 2015-09-11 18:41:17 UTC

Ok thanks for the git bisect.

See bug #738504.

Comment 5 Mikhail Zabaluev 2015-09-11 19:57:11 UTC

Can you isolate the sequence passed to g_utf8_validate() that's causing this?

Comment 6 Mantas Mikulėnas (grawity) 2015-09-11 20:52:24 UTC

(In reply to Mikhail Zabaluev from comment #5)
> Can you isolate the sequence passed to g_utf8_validate() that's causing this?

Causing the crash I don't know, but mistakenly being accepted as valid UTF-8 – a few examples:

 * d2 a1 2f 03 b2 88
 * 55 9d b7 85 86 58
 * 5b 01 28 88 91 24
 * a6 a3 30 64 06 03

Comment 7 Sébastien Wilmet 2015-09-12 09:29:46 UTC

From the backtrace, the sequence is: "\232\251I"

Comment 8 Sébastien Wilmet 2015-09-12 09:42:17 UTC


*** This bug has been marked as a duplicate of bug 738504 ***