Re: [PATCH] nfc: af_nfc: Fix Spectre v1 vulnerability

[David Miller]

From: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Date: Fri, 21 Dec 2018 15:47:53 -0600

> proto is indirectly controlled by user-space, hence leading to
> a potential exploitation of the Spectre variant 1 vulnerability.
> 
> This issue was detected with the help of Smatch:
> 
> net/nfc/af_nfc.c:42 nfc_sock_create() warn: potential spectre issue 'proto_tab' [w] (local cap)
> 
> Fix this by sanitizing proto before using it to index proto_tab.
> 
> Notice that given that speculation windows are large, the policy is
> to kill the speculation on the first load and not worry if it can be
> completed with a dependent load/store [1].
> 
> [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

I'll take this directly, and queued up for -stable.

Thanks.