Merge tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor

Pull apparmor updates from John Johansen:
 "Features:

   - increase left match history buffer size to provide improved
     conflict resolution in overlapping execution rules.

   - switch buffer allocation to use a memory pool and GFP_KERNEL where
     possible.

   - add compression of policy blobs to reduce memory usage.

  Cleanups:

   - fix spelling mistake "immutible" -> "immutable"

  Bug fixes:

   - fix unsigned len comparison in update_for_len macro

   - fix sparse warning for type-casting of current->real_cred"

* tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
  apparmor: make it so work buffers can be allocated from atomic context
  apparmor: reduce rcu_read_lock scope for aa_file_perm mediation
  apparmor: fix wrong buffer allocation in aa_new_mount
  apparmor: fix unsigned len comparison with less than zero
  apparmor: increase left match history buffer size
  apparmor: Switch to GFP_KERNEL where possible
  apparmor: Use a memory pool instead per-CPU caches
  apparmor: Force type-casting of current->real_cred
  apparmor: fix spelling mistake "immutible" -> "immutable"
  apparmor: fix blob compression when ns is forced on a policy load
  apparmor: fix missing ZLIB defines
  apparmor: fix blob compression build failure on ppc
  apparmor: Initial implementation of raw policy blob compression

5 files changed, 13 insertions, 51 deletions

diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h
index 6b7e6e13176e..1fbabdb565a8 100644
--- a/security/apparmor/include/apparmor.h
+++ b/security/apparmor/include/apparmor.h
@@ -36,6 +36,7 @@ extern enum audit_mode aa_g_audit;
 extern bool aa_g_audit_header;
 extern bool aa_g_debug;
 extern bool aa_g_hash_policy;
+extern int aa_g_rawdata_compression_level;
 extern bool aa_g_lock_policy;
 extern bool aa_g_logsyscall;
 extern bool aa_g_paranoid_load;
diff --git a/security/apparmor/include/file.h b/security/apparmor/include/file.h
index a852be89a7dc..aff26fc71407 100644
--- a/security/apparmor/include/file.h
+++ b/security/apparmor/include/file.h
@@ -197,7 +197,7 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry,
 		 const struct path *new_dir, struct dentry *new_dentry);
 
 int aa_file_perm(const char *op, struct aa_label *label, struct file *file,
-		 u32 request);
+		 u32 request, bool in_atomic);
 
 void aa_inherit_files(const struct cred *cred, struct files_struct *files);
 
diff --git a/security/apparmor/include/match.h b/security/apparmor/include/match.h
index 6b0af638a18d..e23f4aadc1ff 100644
--- a/security/apparmor/include/match.h
+++ b/security/apparmor/include/match.h
@@ -134,7 +134,7 @@ unsigned int aa_dfa_matchn_until(struct aa_dfa *dfa, unsigned int start,
 
 void aa_dfa_free_kref(struct kref *kref);
 
-#define WB_HISTORY_SIZE 8
+#define WB_HISTORY_SIZE 24
 struct match_workbuf {
 	unsigned int count;
 	unsigned int pos;
@@ -147,7 +147,6 @@ struct match_workbuf N = {		\
 	.count = 0,			\
 	.pos = 0,			\
 	.len = 0,			\
-	.size = WB_HISTORY_SIZE,			\
 }
 
 unsigned int aa_dfa_leftmatch(struct aa_dfa *dfa, unsigned int start,
diff --git a/security/apparmor/include/path.h b/security/apparmor/include/path.h
index 35a8295e8f3a..44a7945fbe3c 100644
--- a/security/apparmor/include/path.h
+++ b/security/apparmor/include/path.h
@@ -11,7 +11,6 @@
 #ifndef __AA_PATH_H
 #define __AA_PATH_H
 
-
 enum path_flags {
 	PATH_IS_DIR = 0x1,		/* path is a directory */
 	PATH_CONNECT_PATH = 0x4,	/* connect disconnected paths to / */
@@ -26,51 +25,8 @@ int aa_path_name(const struct path *path, int flags, char *buffer,
 		 const char **name, const char **info,
 		 const char *disconnected);
 
-#define MAX_PATH_BUFFERS 2
-
-/* Per cpu buffers used during mediation */
-/* preallocated buffers to use during path lookups */
-struct aa_buffers {
-	char *buf[MAX_PATH_BUFFERS];
-};
-
-#include <linux/percpu.h>
-#include <linux/preempt.h>
-
-DECLARE_PER_CPU(struct aa_buffers, aa_buffers);
-
-#define ASSIGN(FN, A, X, N) ((X) = FN(A, N))
-#define EVAL1(FN, A, X) ASSIGN(FN, A, X, 0) /*X = FN(0)*/
-#define EVAL2(FN, A, X, Y...)	\
-	do { ASSIGN(FN, A, X, 1);  EVAL1(FN, A, Y); } while (0)
-#define EVAL(FN, A, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, A, X)
-
-#define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++)
-
-#ifdef CONFIG_DEBUG_PREEMPT
-#define AA_BUG_PREEMPT_ENABLED(X) AA_BUG(preempt_count() <= 0, X)
-#else
-#define AA_BUG_PREEMPT_ENABLED(X) /* nop */
-#endif
-
-#define __get_buffer(C, N) ({						\
-	AA_BUG_PREEMPT_ENABLED("__get_buffer without preempt disabled");  \
-	(C)->buf[(N)]; })
-
-#define __get_buffers(C, X...)    EVAL(__get_buffer, C, X)
-
-#define __put_buffers(X, Y...) ((void)&(X))
-
-#define get_buffers(X...)						\
-do {									\
-	struct aa_buffers *__cpu_var = get_cpu_ptr(&aa_buffers);	\
-	__get_buffers(__cpu_var, X);					\
-} while (0)
-
-#define put_buffers(X, Y...)		\
-do {					\
-	__put_buffers(X, Y);		\
-	put_cpu_ptr(&aa_buffers);	\
-} while (0)
+#define IN_ATOMIC true
+char *aa_get_buffer(bool in_atomic);
+void aa_put_buffer(char *buf);
 
 #endif /* __AA_PATH_H */
diff --git a/security/apparmor/include/policy_unpack.h b/security/apparmor/include/policy_unpack.h
index 46aefae918f5..e0e1ca7ebc38 100644
--- a/security/apparmor/include/policy_unpack.h
+++ b/security/apparmor/include/policy_unpack.h
@@ -41,6 +41,7 @@ enum {
 	AAFS_LOADDATA_REVISION,
 	AAFS_LOADDATA_HASH,
 	AAFS_LOADDATA_DATA,
+	AAFS_LOADDATA_COMPRESSED_SIZE,
 	AAFS_LOADDATA_DIR,		/* must be last actual entry */
 	AAFS_LOADDATA_NDENTS		/* count of entries */
 };
@@ -61,11 +62,16 @@ struct aa_loaddata {
 	struct dentry *dents[AAFS_LOADDATA_NDENTS];
 	struct aa_ns *ns;
 	char *name;
-	size_t size;
+	size_t size;			/* the original size of the payload */
+	size_t compressed_size;		/* the compressed size of the payload */
 	long revision;			/* the ns policy revision this caused */
 	int abi;
 	unsigned char *hash;
 
+	/* Pointer to payload. If @compressed_size > 0, then this is the
+	 * compressed version of the payload, else it is the uncompressed
+	 * version (with the size indicated by @size).
+	 */
 	char *data;
 };