| Message ID | 20181221214753.GA2799@embeddedor (mailing list archive) |
|---|---|
| State | Deferred |
| Delegated to: | Samuel Ortiz |
| Headers | show |
| Series | nfc: af_nfc: Fix Spectre v1 vulnerability | expand |
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> 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@embeddedor.com> I'll take this directly, and queued up for -stable. Thanks.
On 12/22/18 5:09 PM, David Miller wrote: > From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> > 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@embeddedor.com> > > I'll take this directly, and queued up for -stable. > Dave, I wonder if you can take this one too: https://lore.kernel.org/lkml/20181221212229.GA32635@embeddedor/ It's pretty similar to the af_nfc one. Thanks -- Gustavo
From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> Date: Sat, 22 Dec 2018 17:37:35 -0600 > I wonder if you can take this one too: > > https://lore.kernel.org/lkml/20181221212229.GA32635@embeddedor/ > > It's pretty similar to the af_nfc one. Sure, done.
On 12/22/18 8:42 PM, David Miller wrote: > From: "Gustavo A. R. Silva" <gustavo@embeddedor.com> > Date: Sat, 22 Dec 2018 17:37:35 -0600 > >> I wonder if you can take this one too: >> >> https://lore.kernel.org/lkml/20181221212229.GA32635@embeddedor/ >> >> It's pretty similar to the af_nfc one. > > Sure, done. > Great. Thanks. -- Gustavo
diff --git a/net/nfc/af_nfc.c b/net/nfc/af_nfc.c index d3e594eb36d0..256f3c57059e 100644 --- a/net/nfc/af_nfc.c +++ b/net/nfc/af_nfc.c @@ -21,6 +21,7 @@ #include <linux/nfc.h> #include <linux/module.h> +#include <linux/nospec.h> #include "nfc.h" @@ -37,6 +38,7 @@ static int nfc_sock_create(struct net *net, struct socket *sock, int proto, if (proto < 0 || proto >= NFC_SOCKPROTO_MAX) return -EINVAL; + proto = array_index_nospec(proto, NFC_SOCKPROTO_MAX); read_lock(&proto_tab_lock); if (proto_tab[proto] && try_module_get(proto_tab[proto]->owner)) {
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@embeddedor.com> --- net/nfc/af_nfc.c | 2 ++ 1 file changed, 2 insertions(+)