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Commit 67f0a288 authored by Jeremy Cline's avatar Jeremy Cline Committed by Greg Kroah-Hartman
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netlink: Fix spectre v1 gadget in netlink_create() 



[ 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: default avatarJeremy Cline <jcline@redhat.com>
Reviewed-by: default avatarJosh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ab9a0f80

net/netlink/af_netlink.c

+2 −0
Original line number Diff line number Diff line
@@ -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 *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