2021-05-02 21:37:36

by Phillip Potter

Subject: [PATCH] net: hsr: check skb can contain struct hsr_ethhdr in fill_frame_info

Check at start of fill_frame_info that the MAC header in the supplied
skb is large enough to fit a struct hsr_ethhdr, as otherwise this is
not a valid HSR frame. If it is too small, return an error which will
then cause the callers to clean up the skb. Fixes a KMSAN-found
uninit-value bug reported by syzbot at:
https://syzkaller.appspot.com/bug?id=f7e9b601f1414f814f7602a82b6619a8d80bce3f

Reported-by: [email protected]
Signed-off-by: Phillip Potter <[email protected]>
---
net/hsr/hsr_forward.c | 4 ++++
1 file changed, 4 insertions(+)

diff --git a/net/hsr/hsr_forward.c b/net/hsr/hsr_forward.c
index ed82a470b6e1..f86cdd83e9a8 100644
--- a/net/hsr/hsr_forward.c
+++ b/net/hsr/hsr_forward.c
@@ -520,6 +520,10 @@ static int fill_frame_info(struct hsr_frame_info *frame,
struct ethhdr *ethhdr;
__be16 proto;

+ /* Check if skb contains hsr_ethhdr */
+ if (skb->mac_len < sizeof(struct hsr_ethhdr))
+ return -EINVAL;
+
memset(frame, 0, sizeof(*frame));
frame->is_supervision = is_supervision_frame(port->hsr, skb);
frame->node_src = hsr_get_node(port, &hsr->node_db, skb,
--
2.30.2

2021-05-03 20:44:26

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] net: hsr: check skb can contain struct hsr_ethhdr in fill_frame_info

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Sun, 2 May 2021 22:34:42 +0100 you wrote:
> Check at start of fill_frame_info that the MAC header in the supplied
> skb is large enough to fit a struct hsr_ethhdr, as otherwise this is
> not a valid HSR frame. If it is too small, return an error which will
> then cause the callers to clean up the skb. Fixes a KMSAN-found
> uninit-value bug reported by syzbot at:
> https://syzkaller.appspot.com/bug?id=f7e9b601f1414f814f7602a82b6619a8d80bce3f
>
> [...]

Here is the summary with links:
- net: hsr: check skb can contain struct hsr_ethhdr in fill_frame_info
https://git.kernel.org/netdev/net/c/2e9f60932a2c

You are awesome, thank you!
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