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From: Matthew Wilcox <willy@infradead.org>
To: Linke Li <lilinke99@foxmail.com>
Cc: linux-mm@kvack.org, mike.kravetz@oracle.com,
	muchun.song@linux.dev, nathan@kernel.org,
	ndesaulniers@google.com, trix@redhat.com,
	linux-kernel@vger.kernel.org, llvm@lists.linux.dev,
	dan.carpenter@linaro.org, Linke Li <lilinke99@gmail.com>
Subject: Re: [PATCH v3] hugetlbfs: Fix integer overflow check in hugetlbfs_file_mmap()
Date: Mon, 24 Jul 2023 04:47:33 +0100	[thread overview]
Message-ID: <ZL30Vaj8RYxmsF9o@casper.infradead.org> (raw)
In-Reply-To: <tencent_C2D6865561F23A8141BB145149ACC682B408@qq.com>

On Thu, Jul 20, 2023 at 10:49:52PM +0800, Linke Li wrote:
> +++ b/fs/hugetlbfs/inode.c
> @@ -154,10 +154,7 @@ static int hugetlbfs_file_mmap(struct file *file, struct vm_area_struct *vma)
>  	if (vma->vm_pgoff & (~huge_page_mask(h) >> PAGE_SHIFT))
>  		return -EINVAL;
>  
> -	vma_len = (loff_t)(vma->vm_end - vma->vm_start);
> -	len = vma_len + ((loff_t)vma->vm_pgoff << PAGE_SHIFT);
> -	/* check for overflow */
> -	if (len < vma_len)
> +	if (check_add_overflow(vma_len, (loff_t)vma->vm_pgoff << PAGE_SHIFT, &len))
>  		return -EINVAL;

Doesn't this check duplicate that performed by file_mmap_ok()?  Can't we
just delete the check, or is there a code path that leads here while
avoiding file_mmap_ok()?


  parent reply	other threads:[~2023-07-24  3:47 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-07-20 14:49 [PATCH v3] hugetlbfs: Fix integer overflow check in hugetlbfs_file_mmap() Linke Li
2023-07-20 18:41 ` Mike Kravetz
2023-07-20 19:03 ` Nick Desaulniers
2023-07-20 23:36 ` kernel test robot
2023-07-24  3:47 ` Matthew Wilcox [this message]
2023-07-24 18:59   ` Mike Kravetz
2023-07-24  8:11 ` kernel test robot

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