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From: Byeonguk Jeong <jungbu2855@gmail.com>
To: Hou Tao <houtao@huaweicloud.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>,
	Yonghong Song <yonghong.song@linux.dev>,
	bpf@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] bpf: Fix out-of-bounds write in trie_get_next_key()
Date: Wed, 23 Oct 2024 16:30:06 +0900	[thread overview]
Message-ID: <Zxil/uyqq5qDHuRX@localhost.localdomain> (raw)
In-Reply-To: <26f04a6b-4248-6898-8612-793e02712017@huaweicloud.com>

On Wed, Oct 23, 2024 at 10:03:44AM +0800, Hou Tao wrote:
>
> Without the fix, there will be KASAN report as show below when dumping
> all keys in the lpm-trie through bpf_map_get_next_key().

Thank you for testing.

> 
> However, I have a dumb question: does it make sense to reject the
> element with prefixlen = 0 ? Because I can't think of a use case where a
> zero-length prefix will be useful.

With prefixlen = 0, it would always return -ENOENT, I think. Maybe it is
good to reject it earlier!

  reply	other threads:[~2024-10-23  7:30 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-10-22  1:45 [PATCH] bpf: Fix out-of-bounds write in trie_get_next_key() Byeonguk Jeong
2024-10-22  9:43 ` Toke Høiland-Jørgensen
2024-10-22 19:51 ` Alexei Starovoitov
2024-10-23  1:29   ` Byeonguk Jeong
2024-10-23  8:44   ` Byeonguk Jeong
2024-10-23  2:03 ` Hou Tao
2024-10-23  7:30   ` Byeonguk Jeong [this message]
2024-10-23  9:59     ` Hou Tao
2024-10-24  1:48       ` Byeonguk Jeong
2024-10-24  3:19         ` Hou Tao
2024-10-24  9:08 ` [PATCH] selftests/bpf: Add test for trie_get_next_key() Byeonguk Jeong
2024-10-24  9:41   ` Daniel Borkmann
2024-10-24 22:26     ` Byeonguk Jeong
2024-10-25 11:54       ` Hou Tao
2024-10-25 12:03         ` Daniel Borkmann
2024-10-25 11:53   ` Hou Tao

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