This is a note to let you know that I've just added the patch titled macsec: fix NULL deref in macsec_add_rxsa to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: macsec-fix-null-deref-in-macsec_add_rxsa.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 6b5301e2611221df45c8de07889a609370e4a5de Author: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx> Date: Fri Jul 22 11:16:27 2022 +0200 macsec: fix NULL deref in macsec_add_rxsa [ Upstream commit f46040eeaf2e523a4096199fd93a11e794818009 ] Commit 48ef50fa866a 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: 48ef50fa866a ("macsec: Netlink support of XPN cipher suites (IEEE 802.1AEbw)") Link: https://bugzilla.kernel.org/show_bug.cgi?id=208315 Reported-by: Frantisek Sumsal <fsumsal@xxxxxxxxxx> Signed-off-by: Sabrina Dubroca <sd@xxxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c index 789a124809e3..0b53c7cadd87 100644 --- a/drivers/net/macsec.c +++ b/drivers/net/macsec.c @@ -1750,7 +1750,8 @@ 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();