From: Jinbum Park jinb.park7@gmail.com
[ Upstream commit 3a2af7cccbbaf2362db9053a946a6084e12bfa73 ]
User controls @idx which to be used as index of hwsim_world_regdom_custom. So, It can be exploited via Spectre-like attack. (speculative execution)
This kind of attack leaks address of hwsim_world_regdom_custom, It leads an attacker to bypass security mechanism such as KASLR.
So sanitize @idx before using it to prevent attack.
I leveraged strategy [1] to find and exploit this gadget.
[1] https://github.com/jinb-park/linux-exploit/tree/master/exploit-remaining-spe...
Signed-off-by: Jinbum Park jinb.park7@gmail.com [johannes: unwrap URL] Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Sasha Levin alexander.levin@microsoft.com --- drivers/net/wireless/mac80211_hwsim.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/net/wireless/mac80211_hwsim.c b/drivers/net/wireless/mac80211_hwsim.c index 7d0b460868f9..80e2c8595c7c 100644 --- a/drivers/net/wireless/mac80211_hwsim.c +++ b/drivers/net/wireless/mac80211_hwsim.c @@ -33,6 +33,7 @@ #include <net/net_namespace.h> #include <net/netns/generic.h> #include <linux/rhashtable.h> +#include <linux/nospec.h> #include "mac80211_hwsim.h"
#define WARN_QUEUE 100 @@ -3229,6 +3230,9 @@ static int hwsim_new_radio_nl(struct sk_buff *msg, struct genl_info *info) kfree(hwname); return -EINVAL; } + + idx = array_index_nospec(idx, + ARRAY_SIZE(hwsim_world_regdom_custom)); param.regd = hwsim_world_regdom_custom[idx]; }