Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security subsystem updates from James Morris:
 "Highlights:

   - A new LSM, "LoadPin", from Kees Cook is added, which allows forcing
     of modules and firmware to be loaded from a specific device (this
     is from ChromeOS, where the device as a whole is verified
     cryptographically via dm-verity).

     This is disabled by default but can be configured to be enabled by
     default (don't do this if you don't know what you're doing).

   - Keys: allow authentication data to be stored in an asymmetric key.
     Lots of general fixes and updates.

   - SELinux: add restrictions for loading of kernel modules via
     finit_module().  Distinguish non-init user namespace capability
     checks.  Apply execstack check on thread stacks"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (48 commits)
  LSM: LoadPin: provide enablement CONFIG
  Yama: use atomic allocations when reporting
  seccomp: Fix comment typo
  ima: add support for creating files using the mknodat syscall
  ima: fix ima_inode_post_setattr
  vfs: forbid write access when reading a file into memory
  fs: fix over-zealous use of "const"
  selinux: apply execstack check on thread stacks
  selinux: distinguish non-init user namespace capability checks
  LSM: LoadPin for kernel file loading restrictions
  fs: define a string representation of the kernel_read_file_id enumeration
  Yama: consolidate error reporting
  string_helpers: add kstrdup_quotable_file
  string_helpers: add kstrdup_quotable_cmdline
  string_helpers: add kstrdup_quotable
  selinux: check ss_initialized before revalidating an inode label
  selinux: delay inode label lookup as long as possible
  selinux: don't revalidate an inode's label when explicitly setting it
  selinux: Change bool variable name to index.
  KEYS: Add KEYCTL_DH_COMPUTE command
  ...

1 files changed, 24 insertions, 1 deletions

diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index 391f417..68b26c3 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -246,7 +246,8 @@ static int process_measurement(struct file *file, char *buf, loff_t size,
 		ima_audit_measurement(iint, pathname);
 
 out_digsig:
-	if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG))
+	if ((mask & MAY_WRITE) && (iint->flags & IMA_DIGSIG) &&
+	     !(iint->flags & IMA_NEW_FILE))
 		rc = -EACCES;
 	kfree(xattr_value);
 out_free:
@@ -316,6 +317,28 @@ int ima_file_check(struct file *file, int mask, int opened)
 EXPORT_SYMBOL_GPL(ima_file_check);
 
 /**
+ * ima_post_path_mknod - mark as a new inode
+ * @dentry: newly created dentry
+ *
+ * Mark files created via the mknodat syscall as new, so that the
+ * file data can be written later.
+ */
+void ima_post_path_mknod(struct dentry *dentry)
+{
+	struct integrity_iint_cache *iint;
+	struct inode *inode = dentry->d_inode;
+	int must_appraise;
+
+	must_appraise = ima_must_appraise(inode, MAY_ACCESS, FILE_CHECK);
+	if (!must_appraise)
+		return;
+
+	iint = integrity_inode_get(inode);
+	if (iint)
+		iint->flags |= IMA_NEW_FILE;
+}
+
+/**
  * ima_read_file - pre-measure/appraise hook decision based on policy
  * @file: pointer to the file to be measured/appraised/audit
  * @read_id: caller identifier