4.4-stable review patch. If anyone has any objections, please let me know.
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From: Jeremy Cline jcline@redhat.com
[ 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@redhat.com Signed-off-by: Jeremy Cline jcline@redhat.com Reviewed-by: Josh Poimboeuf jpoimboe@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/netlink/af_netlink.c | 2 ++ 1 file changed, 2 insertions(+)
--- a/net/netlink/af_netlink.c +++ b/net/netlink/af_netlink.c @@ -62,6 +62,7 @@ #include <asm/cacheflush.h> #include <linux/hash.h> #include <linux/genetlink.h> +#include <linux/nospec.h>
#include <net/net_namespace.h> #include <net/sock.h> @@ -654,6 +655,7 @@ 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