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From: Joanne Koong <joannelkoong@gmail.com>
To: bpf@vger.kernel.org
Cc: lorenzo@kernel.org, andrii@kernel.org, daniel@iogearbox.net,
	ast@kernel.org, Joanne Koong <joannelkoong@gmail.com>
Subject: [PATCH bpf-next v1 1/1] bpf: Fix bpf_xdp_pointer return pointer
Date: Fri, 22 Jul 2022 15:01:05 -0700	[thread overview]
Message-ID: <20220722220105.2065466-1-joannelkoong@gmail.com> (raw)

For the case where offset + len == size, bpf_xdp_pointer should return a
valid pointer to the addr because that access is permitted. We should
only return NULL in the case where offset + len exceeds size.

Fixes: 3f364222d032 ("net: xdp: introduce bpf_xdp_pointer utility routine")
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
---
 net/core/filter.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/core/filter.c b/net/core/filter.c
index 289614887ed5..4307a75eeb4c 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -3918,7 +3918,7 @@ static void *bpf_xdp_pointer(struct xdp_buff *xdp, u32 offset, u32 len)
 		offset -= frag_size;
 	}
 out:
-	return offset + len < size ? addr + offset : NULL;
+	return offset + len <= size ? addr + offset : NULL;
 }
 
 BPF_CALL_4(bpf_xdp_load_bytes, struct xdp_buff *, xdp, u32, offset,
-- 
2.30.2


             reply	other threads:[~2022-07-22 22:01 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-07-22 22:01 Joanne Koong [this message]
2022-07-25 20:16 ` [PATCH bpf-next v1 1/1] bpf: Fix bpf_xdp_pointer return pointer Martin KaFai Lau
2022-07-25 21:55   ` Joanne Koong
2022-07-26 11:19     ` Daniel Borkmann
2022-07-25 21:28 ` Lorenzo Bianconi
2022-07-26 11:20 ` patchwork-bot+netdevbpf

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