[libpng12] Fixed undefined behavior in png_push_save_buffer(). Do not call

memcpy() with a null source, even if count is zero (Leon Scroggins III).
This commit is contained in:
Glenn Randers-Pehrson 2016-06-03 21:23:10 -05:00
parent 08e993c056
commit 01a1fd6ea5
3 changed files with 15 additions and 6 deletions

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@ -1,5 +1,5 @@
Libpng 1.2.57beta01 - March 1, 2016 Libpng 1.2.57beta01 - June 4, 2016
This is not intended to be a public release. It will be replaced This is not intended to be a public release. It will be replaced
within a few weeks by a public version or by another test version. within a few weeks by a public version or by another test version.
@ -40,8 +40,10 @@ Other information:
Changes since the last public release (1.2.56): Changes since the last public release (1.2.56):
version 1.2.57beta01 [March 1, 2016] version 1.2.57beta01 [June 4, 2016]
Fix typos in libpng.3 synopses (Eric S. Raymond). Fix typos in libpng.3 synopses (Eric S. Raymond).
Fixed undefined behavior in png_push_save_buffer(). Do not call
memcpy() with a null source, even if count is zero (Leon Scroggins III).
Send comments/corrections/commendations to png-mng-implement at lists.sf.net Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit (subscription required; visit

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@ -2920,8 +2920,10 @@ version 1.2.56rc01 [December 14, 2015]
version 1.2.56 [December 17, 2015] version 1.2.56 [December 17, 2015]
No changes. No changes.
version 1.2.57beta01 [March 1, 2016] version 1.2.57beta01 [June 4, 2016]
Fix typos in libpng.3 synopses (Eric S. Raymond). Fix typos in libpng.3 synopses (Eric S. Raymond).
Fixed undefined behavior in png_push_save_buffer(). Do not call
memcpy() with a null source, even if count is zero (Leon Scroggins III).
Send comments/corrections/commendations to png-mng-implement at lists.sf.net Send comments/corrections/commendations to png-mng-implement at lists.sf.net
(subscription required; visit (subscription required; visit

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@ -1,8 +1,8 @@
/* pngpread.c - read a png file in push mode /* pngpread.c - read a png file in push mode
* *
* Last changed in libpng 1.2.44 [June 26, 2010] * Last changed in libpng 1.2.57 [(TO BE RELEASED)]
* Copyright (c) 1998-2002,2004,2006-2010 Glenn Randers-Pehrson * Copyright (c) 1998-2002,2004,2006-2010,2016 Glenn Randers-Pehrson
* (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger) * (Version 0.96 Copyright (c) 1996, 1997 Andreas Dilger)
* (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.) * (Version 0.88 Copyright (c) 1995, 1996 Guy Eric Schalnat, Group 42, Inc.)
* *
@ -687,7 +687,12 @@ png_push_save_buffer(png_structp png_ptr)
} }
else else
{ {
png_memcpy(png_ptr->save_buffer, old_buffer, png_ptr->save_buffer_size); if (old_buffer)
png_memcpy(png_ptr->save_buffer, old_buffer,
png_ptr->save_buffer_size);
else if (png_ptr->save_buffer_size)
png_error(png_ptr, "save_buffer error");
png_memcpy(png_ptr->save_buffer, old_buffer,png_ptr->save_buffer_size);
png_free(png_ptr, old_buffer); png_free(png_ptr, old_buffer);
png_ptr->save_buffer_max = new_max; png_ptr->save_buffer_max = new_max;
} }