[HN Gopher] Exploring GrapheneOS secure allocator: Hardened Malloc
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       Exploring GrapheneOS secure allocator: Hardened Malloc
        
       Author : r4um
       Score  : 87 points
       Date   : 2025-09-24 09:56 UTC (13 hours ago)
        
 (HTM) web link (www.synacktiv.com)
 (TXT) w3m dump (www.synacktiv.com)
        
       | mrtesthah wrote:
       | Relatedly, check out Apple's own kalloc_type allocator that they
       | use with MTE as well as newer silicon-level changes for extremely
       | broad memory integrity enforcement:
       | 
       | https://security.apple.com/blog/memory-integrity-enforcement...
        
         | pjmlp wrote:
         | Or Solaris SPARC ADI memory allocator,
         | 
         | https://docs.oracle.com/cd/E88353_01/html/E37843/malloc-3c.h...
        
         | pizlonator wrote:
         | Yeah that work is way more impressive.
         | 
         | I like how they demonstrated exactly how it impacts known
         | exploits for example
        
       | pizlonator wrote:
       | The problem with _these kinds_ of hardened allocators is that:
       | 
       | - They impact performance.
       | 
       | - They don't prevent the attacker from pivoting a memory safety
       | bug to remote execution.
       | 
       | - They get oversold (like calling it "secure").
       | 
       | That's not to say there aren't allocator mitigations that help.
       | It's just that this isn't it. Quarantining for example just means
       | the attacker has to do a bit more acrobatics, but it won't stop
       | them.
       | 
       | I think what Apple is doing with typed allocations is much more
       | principled and they have data to prove it in their blog posts
        
         | drnick1 wrote:
         | Yes, but it also means you need an Apple device, and hence a
         | locked down system. You also need to take all of Apple's
         | privacy claims at face value. No thanks.
        
         | manbash wrote:
         | > They don't prevent the attacker from pivoting a memory safety
         | bug to remote execution.
         | 
         | I'm confused. Isn't this potentially preventing some classes of
         | memory-safety bugs?
        
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       (page generated 2025-09-24 23:01 UTC)