selinux: add gfp argument to security_xfrm_policy_alloc and fix callers

security_xfrm_policy_alloc can be called in atomic context so the
allocation should be done with GFP_ATOMIC. Add an argument to let the
callers choose the appropriate way. In order to do so a gfp argument
needs to be added to the method xfrm_policy_alloc_security in struct
security_operations and to the internal function
selinux_xfrm_alloc_user. After that switch to GFP_ATOMIC in the atomic
callers and leave GFP_KERNEL as before for the rest.
The path that needed the gfp argument addition is:
security_xfrm_policy_alloc -> security_ops.xfrm_policy_alloc_security ->
all users of xfrm_policy_alloc_security (e.g. selinux_xfrm_policy_alloc) ->
selinux_xfrm_alloc_user (here the allocation used to be GFP_KERNEL only)

Now adding a gfp argument to selinux_xfrm_alloc_user requires us to also
add it to security_context_to_sid which is used inside and prior to this
patch did only GFP_KERNEL allocation. So add gfp argument to
security_context_to_sid and adjust all of its callers as well.

CC: Paul Moore <paul@paul-moore.com>
CC: Dave Jones <davej@redhat.com>
CC: Steffen Klassert <steffen.klassert@secunet.com>
CC: Fan Du <fan.du@windriver.com>
CC: David S. Miller <davem@davemloft.net>
CC: LSM list <linux-security-module@vger.kernel.org>
CC: SELinux list <selinux@tycho.nsa.gov>

Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>

1 files changed, 3 insertions, 3 deletions

diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c
index c274179d60a2..2f7ddc3a59b4 100644
--- a/net/xfrm/xfrm_user.c
+++ b/net/xfrm/xfrm_user.c
@@ -1221,7 +1221,7 @@ static int copy_from_user_sec_ctx(struct xfrm_policy *pol, struct nlattr **attrs
                 return 0;
 
         uctx = nla_data(rt);
-        return security_xfrm_policy_alloc(&pol->security, uctx);
+        return security_xfrm_policy_alloc(&pol->security, uctx, GFP_KERNEL);
 }
 
 static void copy_templates(struct xfrm_policy *xp, struct xfrm_user_tmpl *ut,
@@ -1626,7 +1626,7 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh,
                 if (rt) {
                         struct xfrm_user_sec_ctx *uctx = nla_data(rt);
 
-                        err = security_xfrm_policy_alloc(&ctx, uctx);
+                        err = security_xfrm_policy_alloc(&ctx, uctx, GFP_KERNEL);
                         if (err)
                                 return err;
                 }
@@ -1928,7 +1928,7 @@ static int xfrm_add_pol_expire(struct sk_buff *skb, struct nlmsghdr *nlh,
                 if (rt) {
                         struct xfrm_user_sec_ctx *uctx = nla_data(rt);
 
-                        err = security_xfrm_policy_alloc(&ctx, uctx);
+                        err = security_xfrm_policy_alloc(&ctx, uctx, GFP_KERNEL);
                         if (err)
                                 return err;
                 }