macsec: always read MACSEC_SA_ATTR_PN as a u64

stable inclusion
from stable-v5.10.135
commit 6e0e0464f1da3eb76695ba231ab7e7e64c2c154f
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5ZWFM

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=6e0e0464f1da3eb76695ba231ab7e7e64c2c154f

--------------------------------

[ Upstream commit c630d1fe ]

Currently, MACSEC_SA_ATTR_PN is handled inconsistently, sometimes as a
u32, sometimes forced into a u64 without checking the actual length of
the attribute. Instead, we can use nla_get_u64 everywhere, which will
read up to 64 bits into a u64, capped by the actual length of the
attribute coming from userspace.

This fixes several issues:
 - the check in validate_add_rxsa doesn't work with 32-bit attributes
 - the checks in validate_add_txsa and validate_upd_sa incorrectly
   reject X << 32 (with X != 0)

Fixes: 48ef50fa ("macsec: Netlink support of XPN cipher suites (IEEE 802.1AEbw)")
Signed-off-by: NSabrina Dubroca <sd@queasysnail.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: NWei Li <liwei391@huawei.com>

drivers/net/macsec.c

@@ -1695,7 +1695,7 @@ static bool validate_add_rxsa(struct nlattr **attrs)
 		return false;
 
 	if (attrs[MACSEC_SA_ATTR_PN] &&
-	    *(u64 *)nla_data(attrs[MACSEC_SA_ATTR_PN]) == 0)
+	    nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 		return false;
 
 	if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
@@ -1938,7 +1938,7 @@ static bool validate_add_txsa(struct nlattr **attrs)
 	if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
 		return false;
 
-	if (nla_get_u32(attrs[MACSEC_SA_ATTR_PN]) == 0)
+	if (nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 		return false;
 
 	if (attrs[MACSEC_SA_ATTR_ACTIVE]) {
@@ -2292,7 +2292,7 @@ static bool validate_upd_sa(struct nlattr **attrs)
 	if (nla_get_u8(attrs[MACSEC_SA_ATTR_AN]) >= MACSEC_NUM_AN)
 		return false;
 
-	if (attrs[MACSEC_SA_ATTR_PN] && nla_get_u32(attrs[MACSEC_SA_ATTR_PN]) == 0)
+	if (attrs[MACSEC_SA_ATTR_PN] && nla_get_u64(attrs[MACSEC_SA_ATTR_PN]) == 0)
 		return false;
 
 	if (attrs[MACSEC_SA_ATTR_ACTIVE]) {