Hello All,

 

Please review the following fix in JDK11 :

 

Bug : https://bugs.openjdk.java.net/browse/JDK-8191023 

Webrev : http://cr.openjdk.java.net/~jdv/8191023/webrev.00/ 

 

Note : Submitter has raised 3 bugs JDK-8191023 , JDK-8191076 , JDK-8191109 with 
similar issue but in 3 different PNG chunks. I have closed two bugs and kept 
first opened JBS bug for this issue. From the closed bug test samples are 
picked and merged into one test case.

 

Issue: When the issue was reported PNGImageReader was throwing 
NegativeArraySizeException when chunk length is malformed and it exceeds 
keyword length. After changes present in 
https://bugs.openjdk.java.net/browse/JDK-8190332 the NegativeArraySizeException 
is wrapped inside IIOException.

 

Exception in thread "main" javax.imageio.IIOException: Caught exception during 
read: 
at 
java.desktop/com.sun.imageio.plugins.png.PNGImageReader.read(PNGImageReader.java:1707)
 
at java.desktop/javax.imageio.ImageIO.read(ImageIO.java:1468) 
at java.desktop/javax.imageio.ImageIO.read(ImageIO.java:1363) 
at 
PngReaderTextChunkKeywordSizeTest.main(PngReaderTextChunkKeywordSizeTest.java:19)
 
Caused by: java.lang.NegativeArraySizeException 
at 
java.desktop/com.sun.imageio.plugins.png.PNGImageReader.parse_tEXt_chunk(PNGImageReader.java:563)
 
at 
java.desktop/com.sun.imageio.plugins.png.PNGImageReader.readMetadata(PNGImageReader.java:816)
 
at 
java.desktop/com.sun.imageio.plugins.png.PNGImageReader.readImage(PNGImageReader.java:1331)
 
at 
java.desktop/com.sun.imageio.plugins.png.PNGImageReader.read(PNGImageReader.java:1700)

 

Root cause : Since the chunk length present is lesser than keyword length. When 
we try to parse individual chunks and create byte Array to store remaining data 
in the chunk. We calculate the byte array size from chunk length and size of 
alreadt parsed data like keyword (like chunkLength - keyword.length() - 2). 
This results in negative value and it causes NegativeArraySizeException when we 
try to create the byte Array.

Solution: Add check in parse function of all the individual chunks to check for 
negative value for the size of the remaining data to be stored. We have PNG 
stream data from 3 bugs with which we can reproduce this issue for zTXt, tEXt 
and iCCP chunk but we don't have stream data for iTXt chunk but still I have 
added similar check in parse_iTXt_chunk() function also.

 

Thanks,

Jay

 

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