From 6d3134025b04a9fad9dc521822288dd3307a50fa Mon Sep 17 00:00:00 2001 From: Sabrina Dubroca Date: Fri, 22 Jul 2022 11:16:27 +0200 Subject: [PATCH] macsec: fix NULL deref in macsec_add_rxsa Commit f5e80c04da34 added a test on tb_sa[MACSEC_SA_ATTR_PN], but nothing guarantees that it's not NULL at this point. The same code was added to macsec_add_txsa, but there it's not a problem because validate_add_txsa checks that the MACSEC_SA_ATTR_PN attribute is present. Note: it's not possible to reproduce with iproute, because iproute doesn't allow creating an SA without specifying the PN. Fixes: f5e80c04da34 ("macsec: Netlink support of XPN cipher suites (IEEE 802.1AEbw)") Link: https://bugzilla.kernel.org/show_bug.cgi?id=208315 Reported-by: Frantisek Sumsal Signed-off-by: Sabrina Dubroca Signed-off-by: David S. Miller --- drivers/net/macsec.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index 817577e713d70..769a1eca6bd8c 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -1753,7 +1753,8 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct genl_info *info) } pn_len = secy->xpn ? MACSEC_XPN_PN_LEN : MACSEC_DEFAULT_PN_LEN; - if (nla_len(tb_sa[MACSEC_SA_ATTR_PN]) != pn_len) { + if (tb_sa[MACSEC_SA_ATTR_PN] && + nla_len(tb_sa[MACSEC_SA_ATTR_PN]) != pn_len) { pr_notice("macsec: nl: add_rxsa: bad pn length: %d != %d\n", nla_len(tb_sa[MACSEC_SA_ATTR_PN]), pn_len); rtnl_unlock(); -- 2.39.5