4.17-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeremy Cline <jcline@xxxxxxxxxx> [ Upstream commit bc5b6c0b62b932626a135f516a41838c510c6eba ] 'protocol' is a user-controlled value, so sanitize it after the bounds check to avoid using it for speculative out-of-bounds access to arrays indexed by it. This addresses the following accesses detected with the help of smatch: * net/netlink/af_netlink.c:654 __netlink_create() warn: potential spectre issue 'nlk_cb_mutex_keys' [w] * net/netlink/af_netlink.c:654 __netlink_create() warn: potential spectre issue 'nlk_cb_mutex_key_strings' [w] * net/netlink/af_netlink.c:685 netlink_create() warn: potential spectre issue 'nl_table' [w] (local cap) Cc: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: Jeremy Cline <jcline@xxxxxxxxxx> Reviewed-by: Josh Poimboeuf <jpoimboe@xxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/netlink/af_netlink.c | 2 ++ 1 file changed, 2 insertions(+) --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -63,6 +63,7 @@ #include <linux/hash.h> #include <linux/genetlink.h> #include <linux/net_namespace.h> +#include <linux/nospec.h> #include <net/net_namespace.h> #include <net/netns/generic.h> @@ -679,6 +680,7 @@ static int netlink_create(struct net *ne if (protocol < 0 || protocol >= MAX_LINKS) return -EPROTONOSUPPORT; + protocol = array_index_nospec(protocol, MAX_LINKS); netlink_lock_table(); #ifdef CONFIG_MODULES
