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| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-12-21 15:47:53 -0600 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-12-22 15:09:25 -0800 |
| commit | a95386f0390ab602904d11fe6bd7ea5ef9b136f8 (patch) | |
| tree | 2468c24c4cfbe9c94218153587273bdd7ec9493b /net | |
| parent | d686026b1e6ed4ea27d630d8f54f9a694db088b2 (diff) | |
| download | linux-a95386f0390ab602904d11fe6bd7ea5ef9b136f8.tar.gz linux-a95386f0390ab602904d11fe6bd7ea5ef9b136f8.tar.bz2 linux-a95386f0390ab602904d11fe6bd7ea5ef9b136f8.zip | |
nfc: af_nfc: Fix Spectre v1 vulnerability
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/nfc/af_nfc.c | 2 |
1 files changed, 2 insertions, 0 deletions
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)) { |