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, 7 insertions, 6 deletions

diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 4b34847208cc..b332e2cc0954 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -668,7 +668,7 @@ static int selinux_set_mnt_opts(struct super_block *sb,
 		if (flags[i] == SBLABEL_MNT)
 			continue;
 		rc = security_context_to_sid(mount_options[i],
-					     strlen(mount_options[i]), &sid);
+					     strlen(mount_options[i]), &sid, GFP_KERNEL);
 		if (rc) {
 			printk(KERN_WARNING "SELinux: security_context_to_sid"
 			       "(%s) failed for (dev %s, type %s) errno=%d\n",
@@ -2489,7 +2489,8 @@ static int selinux_sb_remount(struct super_block *sb, void *data)
 		if (flags[i] == SBLABEL_MNT)
 			continue;
 		len = strlen(mount_options[i]);
-		rc = security_context_to_sid(mount_options[i], len, &sid);
+		rc = security_context_to_sid(mount_options[i], len, &sid,
+					     GFP_KERNEL);
 		if (rc) {
 			printk(KERN_WARNING "SELinux: security_context_to_sid"
 			       "(%s) failed for (dev %s, type %s) errno=%d\n",
@@ -2893,7 +2894,7 @@ static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
 	if (rc)
 		return rc;
 
-	rc = security_context_to_sid(value, size, &newsid);
+	rc = security_context_to_sid(value, size, &newsid, GFP_KERNEL);
 	if (rc == -EINVAL) {
 		if (!capable(CAP_MAC_ADMIN)) {
 			struct audit_buffer *ab;
@@ -3050,7 +3051,7 @@ static int selinux_inode_setsecurity(struct inode *inode, const char *name,
 	if (!value || !size)
 		return -EACCES;
 
-	rc = security_context_to_sid((void *)value, size, &newsid);
+	rc = security_context_to_sid((void *)value, size, &newsid, GFP_KERNEL);
 	if (rc)
 		return rc;
 
@@ -5529,7 +5530,7 @@ static int selinux_setprocattr(struct task_struct *p,
 			str[size-1] = 0;
 			size--;
 		}
-		error = security_context_to_sid(value, size, &sid);
+		error = security_context_to_sid(value, size, &sid, GFP_KERNEL);
 		if (error == -EINVAL && !strcmp(name, "fscreate")) {
 			if (!capable(CAP_MAC_ADMIN)) {
 				struct audit_buffer *ab;
@@ -5638,7 +5639,7 @@ static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
 
 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
 {
-	return security_context_to_sid(secdata, seclen, secid);
+	return security_context_to_sid(secdata, seclen, secid, GFP_KERNEL);
 }
 
 static void selinux_release_secctx(char *secdata, u32 seclen)