Merge tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm

Pull device mapper updates from Mike Snitzer:

 - various fixes and improvements to request-based DM and DM multipath

 - some locking improvements in DM bufio

 - add Kconfig option to disable the DM block manager's extra locking
   which mainly serves as a developer tool

 - a few bug fixes to DM's persistent-data

 - a couple changes to prepare for multipage biovec support in the block
   layer

 - various improvements and cleanups in the DM core, DM cache, DM raid
   and DM crypt

 - add ability to have DM crypt use keys from the kernel key retention
   service

 - add a new "error_writes" feature to the DM flakey target, reads are
   left unchanged in this mode

* tag 'dm-4.10-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/device-mapper/linux-dm: (40 commits)
  dm flakey: introduce "error_writes" feature
  dm cache policy smq: use hash_32() instead of hash_32_generic()
  dm crypt: reject key strings containing whitespace chars
  dm space map: always set ev if sm_ll_mutate() succeeds
  dm space map metadata: skip useless memcpy in metadata_ll_init_index()
  dm space map metadata: fix 'struct sm_metadata' leak on failed create
  Documentation: dm raid: define data_offset status field
  dm raid: fix discard support regression
  dm raid: don't allow "write behind" with raid4/5/6
  dm mpath: use hw_handler_params if attached hw_handler is same as requested
  dm crypt: add ability to use keys from the kernel key retention service
  dm array: remove a dead assignment in populate_ablock_with_values()
  dm ioctl: use offsetof() instead of open-coding it
  dm rq: simplify use_blk_mq initialization
  dm: use blk_set_queue_dying() in __dm_destroy()
  dm bufio: drop the lock when doing GFP_NOIO allocation
  dm bufio: don't take the lock in dm_bufio_shrink_count
  dm bufio: avoid sleeping while holding the dm_bufio lock
  dm table: simplify dm_table_determine_type()
  dm table: an 'all_blk_mq' table must be loaded for a blk-mq DM device
  ...

drivers/md/dm-crypt.c

@@ -12,6 +12,7 @@
 #include <linux/module.h>
 #include <linux/init.h>
 #include <linux/kernel.h>
+#include <linux/key.h>
 #include <linux/bio.h>
 #include <linux/blkdev.h>
 #include <linux/mempool.h>
@@ -23,12 +24,14 @@
 #include <linux/atomic.h>
 #include <linux/scatterlist.h>
 #include <linux/rbtree.h>
+#include <linux/ctype.h>
 #include <asm/page.h>
 #include <asm/unaligned.h>
 #include <crypto/hash.h>
 #include <crypto/md5.h>
 #include <crypto/algapi.h>
 #include <crypto/skcipher.h>
+#include <keys/user-type.h>
 
 #include <linux/device-mapper.h>
 
@@ -140,8 +143,9 @@ struct crypt_config {
 
 	char *cipher;
 	char *cipher_string;
+	char *key_string;
 
-	struct crypt_iv_operations *iv_gen_ops;
+	const struct crypt_iv_operations *iv_gen_ops;
 	union {
 		struct iv_essiv_private essiv;
 		struct iv_benbi_private benbi;
@@ -758,15 +762,15 @@ static int crypt_iv_tcw_post(struct crypt_config *cc, u8 *iv,
 	return r;
 }
 
-static struct crypt_iv_operations crypt_iv_plain_ops = {
+static const struct crypt_iv_operations crypt_iv_plain_ops = {
 	.generator = crypt_iv_plain_gen
 };
 
-static struct crypt_iv_operations crypt_iv_plain64_ops = {
+static const struct crypt_iv_operations crypt_iv_plain64_ops = {
 	.generator = crypt_iv_plain64_gen
 };
 
-static struct crypt_iv_operations crypt_iv_essiv_ops = {
+static const struct crypt_iv_operations crypt_iv_essiv_ops = {
 	.ctr       = crypt_iv_essiv_ctr,
 	.dtr       = crypt_iv_essiv_dtr,
 	.init      = crypt_iv_essiv_init,
@@ -774,17 +778,17 @@ static struct crypt_iv_operations crypt_iv_essiv_ops = {
 	.generator = crypt_iv_essiv_gen
 };
 
-static struct crypt_iv_operations crypt_iv_benbi_ops = {
+static const struct crypt_iv_operations crypt_iv_benbi_ops = {
 	.ctr	   = crypt_iv_benbi_ctr,
 	.dtr	   = crypt_iv_benbi_dtr,
 	.generator = crypt_iv_benbi_gen
 };
 
-static struct crypt_iv_operations crypt_iv_null_ops = {
+static const struct crypt_iv_operations crypt_iv_null_ops = {
 	.generator = crypt_iv_null_gen
 };
 
-static struct crypt_iv_operations crypt_iv_lmk_ops = {
+static const struct crypt_iv_operations crypt_iv_lmk_ops = {
 	.ctr	   = crypt_iv_lmk_ctr,
 	.dtr	   = crypt_iv_lmk_dtr,
 	.init	   = crypt_iv_lmk_init,
@@ -793,7 +797,7 @@ static struct crypt_iv_operations crypt_iv_lmk_ops = {
 	.post	   = crypt_iv_lmk_post
 };
 
-static struct crypt_iv_operations crypt_iv_tcw_ops = {
+static const struct crypt_iv_operations crypt_iv_tcw_ops = {
 	.ctr	   = crypt_iv_tcw_ctr,
 	.dtr	   = crypt_iv_tcw_dtr,
 	.init	   = crypt_iv_tcw_init,
@@ -994,7 +998,6 @@ static struct bio *crypt_alloc_buffer(struct dm_crypt_io *io, unsigned size)
 	gfp_t gfp_mask = GFP_NOWAIT | __GFP_HIGHMEM;
 	unsigned i, len, remaining_size;
 	struct page *page;
-	struct bio_vec *bvec;
 
 retry:
 	if (unlikely(gfp_mask & __GFP_DIRECT_RECLAIM))
@@ -1019,12 +1022,7 @@ retry:
 
 		len = (remaining_size > PAGE_SIZE) ? PAGE_SIZE : remaining_size;
 
-		bvec = &clone->bi_io_vec[clone->bi_vcnt++];
-		bvec->bv_page = page;
-		bvec->bv_len = len;
-		bvec->bv_offset = 0;
-
-		clone->bi_iter.bi_size += len;
+		bio_add_page(clone, page, len, 0);
 
 		remaining_size -= len;
 	}
@@ -1471,7 +1469,7 @@ static int crypt_alloc_tfms(struct crypt_config *cc, char *ciphermode)
 	return 0;
 }
 
-static int crypt_setkey_allcpus(struct crypt_config *cc)
+static int crypt_setkey(struct crypt_config *cc)
 {
 	unsigned subkey_size;
 	int err = 0, i, r;
@@ -1490,25 +1488,157 @@ static int crypt_setkey_allcpus(struct crypt_config *cc)
 	return err;
 }
 
+#ifdef CONFIG_KEYS
+
+static bool contains_whitespace(const char *str)
+{
+	while (*str)
+		if (isspace(*str++))
+			return true;
+	return false;
+}
+
+static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
+{
+	char *new_key_string, *key_desc;
+	int ret;
+	struct key *key;
+	const struct user_key_payload *ukp;
+
+	/*
+	 * Reject key_string with whitespace. dm core currently lacks code for
+	 * proper whitespace escaping in arguments on DM_TABLE_STATUS path.
+	 */
+	if (contains_whitespace(key_string)) {
+		DMERR("whitespace chars not allowed in key string");
+		return -EINVAL;
+	}
+
+	/* look for next ':' separating key_type from key_description */
+	key_desc = strpbrk(key_string, ":");
+	if (!key_desc || key_desc == key_string || !strlen(key_desc + 1))
+		return -EINVAL;
+
+	if (strncmp(key_string, "logon:", key_desc - key_string + 1) &&
+	    strncmp(key_string, "user:", key_desc - key_string + 1))
+		return -EINVAL;
+
+	new_key_string = kstrdup(key_string, GFP_KERNEL);
+	if (!new_key_string)
+		return -ENOMEM;
+
+	key = request_key(key_string[0] == 'l' ? &key_type_logon : &key_type_user,
+			  key_desc + 1, NULL);
+	if (IS_ERR(key)) {
+		kzfree(new_key_string);
+		return PTR_ERR(key);
+	}
+
+	rcu_read_lock();
+
+	ukp = user_key_payload(key);
+	if (!ukp) {
+		rcu_read_unlock();
+		key_put(key);
+		kzfree(new_key_string);
+		return -EKEYREVOKED;
+	}
+
+	if (cc->key_size != ukp->datalen) {
+		rcu_read_unlock();
+		key_put(key);
+		kzfree(new_key_string);
+		return -EINVAL;
+	}
+
+	memcpy(cc->key, ukp->data, cc->key_size);
+
+	rcu_read_unlock();
+	key_put(key);
+
+	/* clear the flag since following operations may invalidate previously valid key */
+	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
+
+	ret = crypt_setkey(cc);
+
+	/* wipe the kernel key payload copy in each case */
+	memset(cc->key, 0, cc->key_size * sizeof(u8));
+
+	if (!ret) {
+		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
+		kzfree(cc->key_string);
+		cc->key_string = new_key_string;
+	} else
+		kzfree(new_key_string);
+
+	return ret;
+}
+
+static int get_key_size(char **key_string)
+{
+	char *colon, dummy;
+	int ret;
+
+	if (*key_string[0] != ':')
+		return strlen(*key_string) >> 1;
+
+	/* look for next ':' in key string */
+	colon = strpbrk(*key_string + 1, ":");
+	if (!colon)
+		return -EINVAL;
+
+	if (sscanf(*key_string + 1, "%u%c", &ret, &dummy) != 2 || dummy != ':')
+		return -EINVAL;
+
+	*key_string = colon;
+
+	/* remaining key string should be :<logon|user>:<key_desc> */
+
+	return ret;
+}
+
+#else
+
+static int crypt_set_keyring_key(struct crypt_config *cc, const char *key_string)
+{
+	return -EINVAL;
+}
+
+static int get_key_size(char **key_string)
+{
+	return (*key_string[0] == ':') ? -EINVAL : strlen(*key_string) >> 1;
+}
+
+#endif
+
 static int crypt_set_key(struct crypt_config *cc, char *key)
 {
 	int r = -EINVAL;
 	int key_string_len = strlen(key);
 
-	/* The key size may not be changed. */
-	if (cc->key_size != (key_string_len >> 1))
-		goto out;
-
 	/* Hyphen (which gives a key_size of zero) means there is no key. */
 	if (!cc->key_size && strcmp(key, "-"))
 		goto out;
 
+	/* ':' means the key is in kernel keyring, short-circuit normal key processing */
+	if (key[0] == ':') {
+		r = crypt_set_keyring_key(cc, key + 1);
+		goto out;
+	}
+
+	/* clear the flag since following operations may invalidate previously valid key */
+	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
+
+	/* wipe references to any kernel keyring key */
+	kzfree(cc->key_string);
+	cc->key_string = NULL;
+
 	if (cc->key_size && crypt_decode_key(cc->key, key, cc->key_size) < 0)
 		goto out;
 
-	set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
-
-	r = crypt_setkey_allcpus(cc);
+	r = crypt_setkey(cc);
+	if (!r)
+		set_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 
 out:
 	/* Hex key string not needed after here, so wipe it. */
@@ -1521,8 +1651,10 @@ static int crypt_wipe_key(struct crypt_config *cc)
 {
 	clear_bit(DM_CRYPT_KEY_VALID, &cc->flags);
 	memset(&cc->key, 0, cc->key_size * sizeof(u8));
+	kzfree(cc->key_string);
+	cc->key_string = NULL;
 
-	return crypt_setkey_allcpus(cc);
+	return crypt_setkey(cc);
 }
 
 static void crypt_dtr(struct dm_target *ti)
@@ -1558,6 +1690,7 @@ static void crypt_dtr(struct dm_target *ti)
 
 	kzfree(cc->cipher);
 	kzfree(cc->cipher_string);
+	kzfree(cc->key_string);
 
 	/* Must zero key material before freeing */
 	kzfree(cc);
@@ -1726,12 +1859,13 @@ bad_mem:
 
 /*
  * Construct an encryption mapping:
- * <cipher> <key> <iv_offset> <dev_path> <start>
+ * <cipher> [<key>|:<key_size>:<user|logon>:<key_description>] <iv_offset> <dev_path> <start>
  */
 static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 {
 	struct crypt_config *cc;
-	unsigned int key_size, opt_params;
+	int key_size;
+	unsigned int opt_params;
 	unsigned long long tmpll;
 	int ret;
 	size_t iv_size_padding;
@@ -1748,7 +1882,11 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		return -EINVAL;
 	}
 
-	key_size = strlen(argv[1]) >> 1;
+	key_size = get_key_size(&argv[1]);
+	if (key_size < 0) {
+		ti->error = "Cannot parse key size";
+		return -EINVAL;
+	}
 
 	cc = kzalloc(sizeof(*cc) + key_size * sizeof(u8), GFP_KERNEL);
 	if (!cc) {
@@ -1955,10 +2093,13 @@ static void crypt_status(struct dm_target *ti, status_type_t type,
 	case STATUSTYPE_TABLE:
 		DMEMIT("%s ", cc->cipher_string);
 
-		if (cc->key_size > 0)
-			for (i = 0; i < cc->key_size; i++)
-				DMEMIT("%02x", cc->key[i]);
-		else
+		if (cc->key_size > 0) {
+			if (cc->key_string)
+				DMEMIT(":%u:%s", cc->key_size, cc->key_string);
+			else
+				for (i = 0; i < cc->key_size; i++)
+					DMEMIT("%02x", cc->key[i]);
+		} else
 			DMEMIT("-");
 
 		DMEMIT(" %llu %s %llu", (unsigned long long)cc->iv_offset,
@@ -2014,7 +2155,7 @@ static void crypt_resume(struct dm_target *ti)
 static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
 {
 	struct crypt_config *cc = ti->private;
-	int ret = -EINVAL;
+	int key_size, ret = -EINVAL;
 
 	if (argc < 2)
 		goto error;
@@ -2025,6 +2166,13 @@ static int crypt_message(struct dm_target *ti, unsigned argc, char **argv)
 			return -EINVAL;
 		}
 		if (argc == 3 && !strcasecmp(argv[1], "set")) {
+			/* The key size may not be changed. */
+			key_size = get_key_size(&argv[2]);
+			if (key_size < 0 || cc->key_size != key_size) {
+				memset(argv[2], '0', strlen(argv[2]));
+				return -EINVAL;
+			}
+
 			ret = crypt_set_key(cc, argv[2]);
 			if (ret)
 				return ret;
@@ -2068,7 +2216,7 @@ static void crypt_io_hints(struct dm_target *ti, struct queue_limits *limits)
 
 static struct target_type crypt_target = {
 	.name   = "crypt",
-	.version = {1, 14, 1},
+	.version = {1, 15, 0},
 	.module = THIS_MODULE,
 	.ctr    = crypt_ctr,
 	.dtr    = crypt_dtr,