From: Xin Long <lucien.xin@xxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Steffen Klassert <steffen.klassert@xxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/xfrm/xfrm_user.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -109,7 +109,8 @@ static inline int verify_sec_ctx_len(str
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;
