diff options
| author | Gustavo A. R. Silva <gustavo@embeddedor.com> | 2018-12-21 15:41:17 -0600 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2018-12-22 15:08:15 -0800 |
| commit | d686026b1e6ed4ea27d630d8f54f9a694db088b2 (patch) | |
| tree | d7bd2f44af64de4131d4dcfb161f6d6c9e18bcc1 /net | |
| parent | 50d5258634aee2e62832aa086d2fb0de00e72b91 (diff) | |
phonet: af_phonet: Fix Spectre v1 vulnerability
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/phonet/af_phonet.c:48 phonet_proto_get() warn: potential spectre issue 'proto_tab' [w] (local cap)
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>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/phonet/af_phonet.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/net/phonet/af_phonet.c b/net/phonet/af_phonet.c index 3b0ef691f5b1..d4b2abd78858 100644 --- a/net/phonet/af_phonet.c +++ b/net/phonet/af_phonet.c @@ -34,6 +34,8 @@ #include <net/phonet/phonet.h> #include <net/phonet/pn_dev.h> +#include <linux/nospec.h> + /* Transport protocol registration */ static const struct phonet_protocol *proto_tab[PHONET_NPROTO] __read_mostly; @@ -43,6 +45,7 @@ static const struct phonet_protocol *phonet_proto_get(unsigned int protocol) if (protocol >= PHONET_NPROTO) return NULL; + protocol = array_index_nospec(protocol, PHONET_NPROTO); rcu_read_lock(); pp = rcu_dereference(proto_tab[protocol]); |