From bc5b6c0b62b932626a135f516a41838c510c6eba Mon Sep 17 00:00:00 2001 From: Jeremy Cline Date: Tue, 31 Jul 2018 21:13:16 +0000 Subject: netlink: Fix spectre v1 gadget in netlink_create() '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 Signed-off-by: Jeremy Cline Reviewed-by: Josh Poimboeuf Signed-off-by: David S. Miller --- net/netlink/af_netlink.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'net/netlink') diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c index 7d860a22e5fb..c09d16870f74 100644 --- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -63,6 +63,7 @@ #include #include #include +#include #include #include @@ -679,6 +680,7 @@ static int netlink_create(struct net *net, struct socket *sock, int protocol, if (protocol < 0 || protocol >= MAX_LINKS) return -EPROTONOSUPPORT; + protocol = array_index_nospec(protocol, MAX_LINKS); netlink_lock_table(); #ifdef CONFIG_MODULES -- cgit v1.2.3-55-g7522