Re: Corrupted heap

[David Chisnall]

On 18 Mar 2010, at 12:02, Vincent Richomme wrote:

> When debugger returns from 004045C1  call eax, I get a nice popup 
> with the error message :
> 
> 7c97f749: The instruction at 0x7c97f749 referenced memory at 0x40000058.
> The memory cannot be read...


%eax is the register used for returning integer / pointer values.  The call eax 
is calling the function returned from objc_msg_lookup().  

The call before this is objc_get_class, so it's sending a class message. I 
think the class is NSImage.  I'm not used to reading Intel format asm, but the 
selector is the second argument to objc_msg_lookup.  This would be passed in 
ebx on most x86 ABIs that I'm familiar with, but it seems to be being stored on 
the stack here?  I think it is the value at offset off_40A090.

David

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