Messages in this thread | ![/](/images/icornerl.gif) | | Subject | Re: [PATCH] can: af_can: Fix Spectre v1 vulnerability | From | Oliver Hartkopp <> | Date | Sun, 23 Dec 2018 20:02:18 +0100 |
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After *trying* to follow the discussion on ...
https://marc.info/?l=linux-kernel&m=154554485324143&w=2 [PATCH] net: core: Fix Spectre v1 vulnerability
... I'm still not sure whether af_can.c needs this enhancement or not.
Just waiting for the end of the discussion :-)
Thanks to the experts!
Oliver
On 12/21/18 10:22 PM, Gustavo A. R. Silva wrote: > protocol 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/can/af_can.c:115 can_get_proto() warn: potential spectre issue 'proto_tab' [w] > > Fix this by sanitizing protocol 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@embeddedor.com> > --- > net/can/af_can.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/net/can/af_can.c b/net/can/af_can.c > index 1684ba5b51eb..cade7250c6d4 100644 > --- a/net/can/af_can.c > +++ b/net/can/af_can.c > @@ -59,6 +59,7 @@ > #include <linux/can/core.h> > #include <linux/can/skb.h> > #include <linux/ratelimit.h> > +#include <linux/nospec.h> > #include <net/net_namespace.h> > #include <net/sock.h> > > @@ -136,6 +137,7 @@ static int can_create(struct net *net, struct socket *sock, int protocol, > > if (protocol < 0 || protocol >= CAN_NPROTO) > return -EINVAL; > + protocol = array_index_nospec(protocol, CAN_NPROTO); > > cp = can_get_proto(protocol); > >
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