netdev - [PATCH 10/12] xfrm: validate assignment of maximal possible SEQ number

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250523075611.3723340-11-steffen.klassert@secunet.com>
Date: Fri, 23 May 2025 09:56:09 +0200
From: Steffen Klassert <steffen.klassert@...unet.com>
To: David Miller <davem@...emloft.net>, Jakub Kicinski <kuba@...nel.org>
CC: Herbert Xu <herbert@...dor.apana.org.au>, Steffen Klassert
	<steffen.klassert@...unet.com>, <netdev@...r.kernel.org>
Subject: [PATCH 10/12] xfrm: validate assignment of maximal possible SEQ number

From: Leon Romanovsky <leonro@...dia.com>

Users can set any seq/seq_hi/oseq/oseq_hi values. The XFRM core code
doesn't prevent from them to set even 0xFFFFFFFF, however this value
will cause for traffic drop.

Is is happening because SEQ numbers here mean that packet with such
number was processed and next number should be sent on the wire. In this
case, the next number will be 0, and it means overflow which causes to
(expected) packet drops.

While it can be considered as misconfiguration and handled by XFRM
datapath in the same manner as any other SEQ number, let's add
validation to easy for packet offloads implementations which need to
configure HW with next SEQ to send and not with current SEQ like it is
done in core code.

Signed-off-by: Leon Romanovsky <leonro@...dia.com>
Signed-off-by: Steffen Klassert <steffen.klassert@...unet.com>
---
 net/xfrm/xfrm_user.c | 52 +++++++++++++++++++++++++++++++++++---------
 1 file changed, 42 insertions(+), 10 deletions(-)

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index ae8e06573639..59f258daf830 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -178,11 +178,27 @@ static inline int verify_replay(struct xfrm_usersa_info *p,
 				       "Replay seq and seq_hi should be 0 for output SA");
 			return -EINVAL;
 		}
-		if (rs->oseq_hi && !(p->flags & XFRM_STATE_ESN)) {
-			NL_SET_ERR_MSG(
-				extack,
-				"Replay oseq_hi should be 0 in non-ESN mode for output SA");
-			return -EINVAL;
+
+		if (!(p->flags & XFRM_STATE_ESN)) {
+			if (rs->oseq_hi) {
+				NL_SET_ERR_MSG(
+					extack,
+					"Replay oseq_hi should be 0 in non-ESN mode for output SA");
+				return -EINVAL;
+			}
+			if (rs->oseq == U32_MAX) {
+				NL_SET_ERR_MSG(
+					extack,
+					"Replay oseq should be less than 0xFFFFFFFF in non-ESN mode for output SA");
+				return -EINVAL;
+			}
+		} else {
+			if (rs->oseq == U32_MAX && rs->oseq_hi == U32_MAX) {
+				NL_SET_ERR_MSG(
+					extack,
+					"Replay oseq and oseq_hi should be less than 0xFFFFFFFF for output SA");
+				return -EINVAL;
+			}
 		}
 		if (rs->bmp_len) {
 			NL_SET_ERR_MSG(extack, "Replay bmp_len should 0 for output SA");
@@ -196,11 +212,27 @@ static inline int verify_replay(struct xfrm_usersa_info *p,
 				       "Replay oseq and oseq_hi should be 0 for input SA");
 			return -EINVAL;
 		}
-		if (rs->seq_hi && !(p->flags & XFRM_STATE_ESN)) {
-			NL_SET_ERR_MSG(
-				extack,
-				"Replay seq_hi should be 0 in non-ESN mode for input SA");
-			return -EINVAL;
+		if (!(p->flags & XFRM_STATE_ESN)) {
+			if (rs->seq_hi) {
+				NL_SET_ERR_MSG(
+					extack,
+					"Replay seq_hi should be 0 in non-ESN mode for input SA");
+				return -EINVAL;
+			}
+
+			if (rs->seq == U32_MAX) {
+				NL_SET_ERR_MSG(
+					extack,
+					"Replay seq should be less than 0xFFFFFFFF in non-ESN mode for input SA");
+				return -EINVAL;
+			}
+		} else {
+			if (rs->seq == U32_MAX && rs->seq_hi == U32_MAX) {
+				NL_SET_ERR_MSG(
+					extack,
+					"Replay seq and seq_hi should be less than 0xFFFFFFFF for input SA");
+				return -EINVAL;
+			}
 		}
 	}
 
-- 
2.34.1