blob: e367547de4c9aa68f952e1cfe2196156540373b1 [file] [log] [blame]
From 2b6e11548a9fcf3613fb301772ff277f45e98fab Mon Sep 17 00:00:00 2001
From: Xin Long <lucien.xin@gmail.com>
Date: Sun, 9 Feb 2020 21:15:29 +0800
Subject: [PATCH] xfrm: fix uctx len check in verify_sec_ctx_len
commit 171d449a028573b2f0acdc7f31ecbb045391b320 upstream.
It's not sufficient to do 'uctx->len != (sizeof(struct xfrm_user_sec_ctx) +
uctx->ctx_len)' check only, as uctx->len may be greater than nla_len(rt),
in which case it will cause slab-out-of-bounds when accessing uctx->ctx_str
later.
This patch is to fix it by return -EINVAL when uctx->len > nla_len(rt).
Fixes: df71837d5024 ("[LSM-IPSec]: Security association restriction.")
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index b88ba45ff1ac..38ff02d31402 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -110,7 +110,8 @@ static inline int verify_sec_ctx_len(struct nlattr **attrs)
return 0;
uctx = nla_data(rt);
- if (uctx->len != (sizeof(struct xfrm_user_sec_ctx) + uctx->ctx_len))
+ if (uctx->len > nla_len(rt) ||
+ uctx->len != (sizeof(struct xfrm_user_sec_ctx) + uctx->ctx_len))
return -EINVAL;
return 0;
--
2.7.4