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, 18 insertions, 10 deletions

diff --git a/security/selinux/selinuxfs.c b/security/selinux/selinuxfs.c
index 5122affe06a8..d60c0ee66387 100644
--- a/security/selinux/selinuxfs.c
+++ b/security/selinux/selinuxfs.c
@@ -576,7 +576,7 @@ static ssize_t sel_write_context(struct file *file, char *buf, size_t size)
 	if (length)
 		goto out;
 
-	length = security_context_to_sid(buf, size, &sid);
+	length = security_context_to_sid(buf, size, &sid, GFP_KERNEL);
 	if (length)
 		goto out;
 
@@ -731,11 +731,13 @@ static ssize_t sel_write_access(struct file *file, char *buf, size_t size)
 	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 		goto out;
 
-	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
+	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
+					 GFP_KERNEL);
 	if (length)
 		goto out;
 
-	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
+	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
+					 GFP_KERNEL);
 	if (length)
 		goto out;
 
@@ -817,11 +819,13 @@ static ssize_t sel_write_create(struct file *file, char *buf, size_t size)
 		objname = namebuf;
 	}
 
-	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
+	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
+					 GFP_KERNEL);
 	if (length)
 		goto out;
 
-	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
+	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
+					 GFP_KERNEL);
 	if (length)
 		goto out;
 
@@ -878,11 +882,13 @@ static ssize_t sel_write_relabel(struct file *file, char *buf, size_t size)
 	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 		goto out;
 
-	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
+	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
+					 GFP_KERNEL);
 	if (length)
 		goto out;
 
-	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
+	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
+					 GFP_KERNEL);
 	if (length)
 		goto out;
 
@@ -934,7 +940,7 @@ static ssize_t sel_write_user(struct file *file, char *buf, size_t size)
 	if (sscanf(buf, "%s %s", con, user) != 2)
 		goto out;
 
-	length = security_context_to_sid(con, strlen(con) + 1, &sid);
+	length = security_context_to_sid(con, strlen(con) + 1, &sid, GFP_KERNEL);
 	if (length)
 		goto out;
 
@@ -994,11 +1000,13 @@ static ssize_t sel_write_member(struct file *file, char *buf, size_t size)
 	if (sscanf(buf, "%s %s %hu", scon, tcon, &tclass) != 3)
 		goto out;
 
-	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid);
+	length = security_context_to_sid(scon, strlen(scon) + 1, &ssid,
+					 GFP_KERNEL);
 	if (length)
 		goto out;
 
-	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid);
+	length = security_context_to_sid(tcon, strlen(tcon) + 1, &tsid,
+					 GFP_KERNEL);
 	if (length)
 		goto out;