2022-11-22 02:53:28

by Rong Tao

Subject: [PATCH bpf-next] samples/bpf: xdp_router_ipv4_user: Fix write overflow

From: Rong Tao <[email protected]>

prefix_key->data allocates three bytes using alloca(), but four bytes are
accessed in the program.

Signed-off-by: Rong Tao <[email protected]>
---
samples/bpf/xdp_router_ipv4_user.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/samples/bpf/xdp_router_ipv4_user.c b/samples/bpf/xdp_router_ipv4_user.c
index 683913bbf279..9d41db09c480 100644
--- a/samples/bpf/xdp_router_ipv4_user.c
+++ b/samples/bpf/xdp_router_ipv4_user.c
@@ -162,7 +162,7 @@ static void read_route(struct nlmsghdr *nh, int nll)
__be32 gw;
} *prefix_value;

- prefix_key = alloca(sizeof(*prefix_key) + 3);
+ prefix_key = alloca(sizeof(*prefix_key) + 4);
prefix_value = alloca(sizeof(*prefix_value));

prefix_key->prefixlen = 32;
--
2.38.1

2022-11-25 00:39:10

by patchwork-bot+netdevbpf

Subject: Re: [PATCH bpf-next] samples/bpf: xdp_router_ipv4_user: Fix write overflow

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Daniel Borkmann <[email protected]>:

On Tue, 22 Nov 2022 10:32:56 +0800 you wrote:
> From: Rong Tao <[email protected]>
>
> prefix_key->data allocates three bytes using alloca(), but four bytes are
> accessed in the program.
>
> Signed-off-by: Rong Tao <[email protected]>
>
> [...]

Here is the summary with links:
- [bpf-next] samples/bpf: xdp_router_ipv4_user: Fix write overflow
https://git.kernel.org/bpf/bpf-next/c/19a2bdbaaddc

You are awesome, thank you!
--
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