Re: [PATCH] net: atm: Fix potential Spectre v1 vulnerabilities

[David Miller]

From: "Gustavo A. R. Silva" <gustavo@xxxxxxxxxxxxxx>
Date: Mon, 15 Apr 2019 15:57:23 -0500

> arg is 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/atm/lec.c:715 lec_mcast_attach() warn: potential spectre issue 'dev_lec' [r] (local cap)
> 
> Fix this by sanitizing arg before using it to index dev_lec.
> 
> 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://lore.kernel.org/lkml/20180423164740.GY17484@xxxxxxxxxxxxxx/
> 
> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>

Applied and queued up for -stable.