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Date: Thu, 25 Apr 2024 13:53:15 +0100
From: Matthew Wilcox <willy@infradead.org>
To: Jeongjun Park <aha310510@gmail.com>
Cc: brauner@kernel.org, eadavis@qq.com,
	jfs-discussion@lists.sourceforge.net, jlayton@kernel.org,
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Subject: Re: [PATCH] jfs: Fix array-index-out-of-bounds in diFree
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 <20240425124433.28645-1-aha310510@gmail.com>
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On Thu, Apr 25, 2024 at 09:44:33PM +0900, Jeongjun Park wrote:
> Through direct testing and debugging, I've determined that this 
> vulnerability occurs when mounting an incorrect image, leading to 
> the potential passing of an excessively large value to 
> 'sbi->bmap->db_agl2size'. Importantly, there have been no instances 
> of memory corruption observed within 'sbi->bmap->db_agl2size'. 
> 
> Therefore, I think implementing a patch that terminates the 
> function in cases where an invalid value is detected.

If that's the problem then the correct place to detect & reject this is
during mount, not at inode free time.