From: Eric Dumazet edumazet@google.com
[ Upstream commit b6ee896385380aa621102e8ea402ba12db1cabff ]
int type = nla_type(nla);
if (type > XFRMA_MAX) { return -EOPNOTSUPP; }
@type is then used as an array index and can be used as a Spectre v1 gadget.
if (nla_len(nla) < compat_policy[type].len) {
array_index_nospec() can be used to prevent leaking content of kernel memory to malicious users.
Fixes: 5106f4a8acff ("xfrm/compat: Add 32=>64-bit messages translator") Signed-off-by: Eric Dumazet edumazet@google.com Cc: Dmitry Safonov dima@arista.com Cc: Steffen Klassert steffen.klassert@secunet.com Reviewed-by: Dmitry Safonov dima@arista.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/xfrm/xfrm_compat.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/net/xfrm/xfrm_compat.c b/net/xfrm/xfrm_compat.c index 12405aa5bce84..8cbf45a8bcdc2 100644 --- a/net/xfrm/xfrm_compat.c +++ b/net/xfrm/xfrm_compat.c @@ -5,6 +5,7 @@ * Based on code and translator idea by: Florian Westphal fw@strlen.de */ #include <linux/compat.h> +#include <linux/nospec.h> #include <linux/xfrm.h> #include <net/xfrm.h>
@@ -437,6 +438,7 @@ static int xfrm_xlate32_attr(void *dst, const struct nlattr *nla, NL_SET_ERR_MSG(extack, "Bad attribute"); return -EOPNOTSUPP; } + type = array_index_nospec(type, XFRMA_MAX + 1); if (nla_len(nla) < compat_policy[type].len) { NL_SET_ERR_MSG(extack, "Attribute bad length"); return -EOPNOTSUPP;