From: Leon Romanovsky leonro@nvidia.com
commit 7c76ecd9c99b6e9a771d813ab1aa7fa428b3ade1 upstream.
struct xfrm_user_offload has flags variable that received user input, but kernel didn't check if valid bits were provided. It caused a situation where not sanitized input was forwarded directly to the drivers.
For example, XFRM_OFFLOAD_IPV6 define that was exposed, was used by strongswan, but not implemented in the kernel at all.
As a solution, check and sanitize input flags to forward XFRM_OFFLOAD_INBOUND to the drivers.
Fixes: d77e38e612a0 ("xfrm: Add an IPsec hardware offloading API") Signed-off-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- include/uapi/linux/xfrm.h | 6 ++++++ net/xfrm/xfrm_device.c | 6 +++++- 2 files changed, 11 insertions(+), 1 deletion(-)
--- a/include/uapi/linux/xfrm.h +++ b/include/uapi/linux/xfrm.h @@ -506,6 +506,12 @@ struct xfrm_user_offload { int ifindex; __u8 flags; }; +/* This flag was exposed without any kernel code that supporting it. + * Unfortunately, strongswan has the code that uses sets this flag, + * which makes impossible to reuse this bit. + * + * So leave it here to make sure that it won't be reused by mistake. + */ #define XFRM_OFFLOAD_IPV6 1 #define XFRM_OFFLOAD_INBOUND 2
--- a/net/xfrm/xfrm_device.c +++ b/net/xfrm/xfrm_device.c @@ -223,6 +223,9 @@ int xfrm_dev_state_add(struct net *net, if (x->encap || x->tfcpad) return -EINVAL;
+ if (xuo->flags & ~(XFRM_OFFLOAD_IPV6 | XFRM_OFFLOAD_INBOUND)) + return -EINVAL; + dev = dev_get_by_index(net, xuo->ifindex); if (!dev) { if (!(xuo->flags & XFRM_OFFLOAD_INBOUND)) { @@ -261,7 +264,8 @@ int xfrm_dev_state_add(struct net *net, xso->dev = dev; xso->real_dev = dev; xso->num_exthdrs = 1; - xso->flags = xuo->flags; + /* Don't forward bit that is not implemented */ + xso->flags = xuo->flags & ~XFRM_OFFLOAD_IPV6;
err = dev->xfrmdev_ops->xdo_dev_state_add(x); if (err) {