Merge tag 'v3.14.56' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable into linux-linaro-lsk-v3.14

This is the 3.14.56 stable release

# gpg: Signature made Mon Oct 26 17:46:33 2015 PDT using RSA key ID 6092693E
# gpg: Good signature from "Greg Kroah-Hartman (Linux kernel stable release signing key) <greg@kroah.com>"

* tag 'v3.14.56' of git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable: (106 commits)
  Linux 3.14.56
  sched/preempt: Fix cond_resched_lock() and cond_resched_softirq()
  sched/preempt: Rename PREEMPT_CHECK_OFFSET to PREEMPT_DISABLE_OFFSET
  rbd: fix double free on rbd_dev->header_name
  dm thin: fix missing pool reference count decrement in pool_ctr error path
  drm/radeon: add pm sysfs files late
  drm/nouveau/fbcon: take runpm reference when userspace has an open fd
  workqueue: make sure delayed work run in local cpu
  i2c: designware: Do not use parameters from ACPI on Dell Inspiron 7348
  i2c: s3c2410: enable RuntimePM before registering to the core
  i2c: rcar: enable RuntimePM before registering to the core
  arm64: errata: use KBUILD_CFLAGS_MODULE for erratum #843419
  btrfs: fix use after free iterating extrefs
  crypto: ahash - ensure statesize is non-zero
  crypto: sparc - initialize blkcipher.ivsize
  asix: Do full reset during ax88772_bind
  asix: Don't reset PHY on if_up for ASIX 88772
  ethtool: Use kcalloc instead of kmalloc for ethtool_get_strings
  ppp: don't override sk->sk_state in pppoe_flush_dev()
  net: add pfmemalloc check in sk_add_backlog()
  ...

10 files changed, 207 insertions, 35 deletions

diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c
index 6244f9cf8ae3..0529defbdf73 100644
--- a/fs/btrfs/backref.c
+++ b/fs/btrfs/backref.c
@@ -1692,7 +1692,6 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root,
 	int found = 0;
 	struct extent_buffer *eb;
 	struct btrfs_inode_extref *extref;
-	struct extent_buffer *leaf;
 	u32 item_size;
 	u32 cur_offset;
 	unsigned long ptr;
@@ -1720,9 +1719,8 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root,
 		btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK);
 		btrfs_release_path(path);
 
-		leaf = path->nodes[0];
-		item_size = btrfs_item_size_nr(leaf, slot);
-		ptr = btrfs_item_ptr_offset(leaf, slot);
+		item_size = btrfs_item_size_nr(eb, slot);
+		ptr = btrfs_item_ptr_offset(eb, slot);
 		cur_offset = 0;
 
 		while (cur_offset < item_size) {
@@ -1736,7 +1734,7 @@ static int iterate_inode_extrefs(u64 inum, struct btrfs_root *fs_root,
 			if (ret)
 				break;
 
-			cur_offset += btrfs_inode_extref_name_len(leaf, extref);
+			cur_offset += btrfs_inode_extref_name_len(eb, extref);
 			cur_offset += sizeof(*extref);
 		}
 		btrfs_tree_read_unlock_blocking(eb);
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index 8adfc65b37dd..332999288b51 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2681,7 +2681,8 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
 			      bio_end_io_t end_io_func,
 			      int mirror_num,
 			      unsigned long prev_bio_flags,
-			      unsigned long bio_flags)
+			      unsigned long bio_flags,
+			      bool force_bio_submit)
 {
 	int ret = 0;
 	struct bio *bio;
@@ -2699,6 +2700,7 @@ static int submit_extent_page(int rw, struct extent_io_tree *tree,
 			contig = bio_end_sector(bio) == sector;
 
 		if (prev_bio_flags != bio_flags || !contig ||
+		    force_bio_submit ||
 		    merge_bio(rw, tree, page, offset, page_size, bio, bio_flags) ||
 		    bio_add_page(bio, page, page_size, offset) < page_size) {
 			ret = submit_one_bio(rw, bio, mirror_num,
@@ -2790,7 +2792,8 @@ static int __do_readpage(struct extent_io_tree *tree,
 			 get_extent_t *get_extent,
 			 struct extent_map **em_cached,
 			 struct bio **bio, int mirror_num,
-			 unsigned long *bio_flags, int rw)
+			 unsigned long *bio_flags, int rw,
+			 u64 *prev_em_start)
 {
 	struct inode *inode = page->mapping->host;
 	u64 start = page_offset(page);
@@ -2838,6 +2841,7 @@ static int __do_readpage(struct extent_io_tree *tree,
 	}
 	while (cur <= end) {
 		unsigned long pnr = (last_byte >> PAGE_CACHE_SHIFT) + 1;
+		bool force_bio_submit = false;
 
 		if (cur >= last_byte) {
 			char *userpage;
@@ -2888,6 +2892,49 @@ static int __do_readpage(struct extent_io_tree *tree,
 		block_start = em->block_start;
 		if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
 			block_start = EXTENT_MAP_HOLE;
+
+		/*
+		 * If we have a file range that points to a compressed extent
+		 * and it's followed by a consecutive file range that points to
+		 * to the same compressed extent (possibly with a different
+		 * offset and/or length, so it either points to the whole extent
+		 * or only part of it), we must make sure we do not submit a
+		 * single bio to populate the pages for the 2 ranges because
+		 * this makes the compressed extent read zero out the pages
+		 * belonging to the 2nd range. Imagine the following scenario:
+		 *
+		 *  File layout
+		 *  [0 - 8K]                     [8K - 24K]
+		 *    |                               |
+		 *    |                               |
+		 * points to extent X,         points to extent X,
+		 * offset 4K, length of 8K     offset 0, length 16K
+		 *
+		 * [extent X, compressed length = 4K uncompressed length = 16K]
+		 *
+		 * If the bio to read the compressed extent covers both ranges,
+		 * it will decompress extent X into the pages belonging to the
+		 * first range and then it will stop, zeroing out the remaining
+		 * pages that belong to the other range that points to extent X.
+		 * So here we make sure we submit 2 bios, one for the first
+		 * range and another one for the third range. Both will target
+		 * the same physical extent from disk, but we can't currently
+		 * make the compressed bio endio callback populate the pages
+		 * for both ranges because each compressed bio is tightly
+		 * coupled with a single extent map, and each range can have
+		 * an extent map with a different offset value relative to the
+		 * uncompressed data of our extent and different lengths. This
+		 * is a corner case so we prioritize correctness over
+		 * non-optimal behavior (submitting 2 bios for the same extent).
+		 */
+		if (test_bit(EXTENT_FLAG_COMPRESSED, &em->flags) &&
+		    prev_em_start && *prev_em_start != (u64)-1 &&
+		    *prev_em_start != em->orig_start)
+			force_bio_submit = true;
+
+		if (prev_em_start)
+			*prev_em_start = em->orig_start;
+
 		free_extent_map(em);
 		em = NULL;
 
@@ -2937,7 +2984,8 @@ static int __do_readpage(struct extent_io_tree *tree,
 					 bdev, bio, pnr,
 					 end_bio_extent_readpage, mirror_num,
 					 *bio_flags,
-					 this_bio_flag);
+					 this_bio_flag,
+					 force_bio_submit);
 		if (!ret) {
 			nr++;
 			*bio_flags = this_bio_flag;
@@ -2964,7 +3012,8 @@ static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
 					     get_extent_t *get_extent,
 					     struct extent_map **em_cached,
 					     struct bio **bio, int mirror_num,
-					     unsigned long *bio_flags, int rw)
+					     unsigned long *bio_flags, int rw,
+					     u64 *prev_em_start)
 {
 	struct inode *inode;
 	struct btrfs_ordered_extent *ordered;
@@ -2984,7 +3033,7 @@ static inline void __do_contiguous_readpages(struct extent_io_tree *tree,
 
 	for (index = 0; index < nr_pages; index++) {
 		__do_readpage(tree, pages[index], get_extent, em_cached, bio,
-			      mirror_num, bio_flags, rw);
+			      mirror_num, bio_flags, rw, prev_em_start);
 		page_cache_release(pages[index]);
 	}
 }
@@ -2994,7 +3043,8 @@ static void __extent_readpages(struct extent_io_tree *tree,
 			       int nr_pages, get_extent_t *get_extent,
 			       struct extent_map **em_cached,
 			       struct bio **bio, int mirror_num,
-			       unsigned long *bio_flags, int rw)
+			       unsigned long *bio_flags, int rw,
+			       u64 *prev_em_start)
 {
 	u64 start = 0;
 	u64 end = 0;
@@ -3015,7 +3065,7 @@ static void __extent_readpages(struct extent_io_tree *tree,
 						  index - first_index, start,
 						  end, get_extent, em_cached,
 						  bio, mirror_num, bio_flags,
-						  rw);
+						  rw, prev_em_start);
 			start = page_start;
 			end = start + PAGE_CACHE_SIZE - 1;
 			first_index = index;
@@ -3026,7 +3076,8 @@ static void __extent_readpages(struct extent_io_tree *tree,
 		__do_contiguous_readpages(tree, &pages[first_index],
 					  index - first_index, start,
 					  end, get_extent, em_cached, bio,
-					  mirror_num, bio_flags, rw);
+					  mirror_num, bio_flags, rw,
+					  prev_em_start);
 }
 
 static int __extent_read_full_page(struct extent_io_tree *tree,
@@ -3052,7 +3103,7 @@ static int __extent_read_full_page(struct extent_io_tree *tree,
 	}
 
 	ret = __do_readpage(tree, page, get_extent, NULL, bio, mirror_num,
-			    bio_flags, rw);
+			    bio_flags, rw, NULL);
 	return ret;
 }
 
@@ -3078,7 +3129,7 @@ int extent_read_full_page_nolock(struct extent_io_tree *tree, struct page *page,
 	int ret;
 
 	ret = __do_readpage(tree, page, get_extent, NULL, &bio, mirror_num,
-				      &bio_flags, READ);
+			    &bio_flags, READ, NULL);
 	if (bio)
 		ret = submit_one_bio(READ, bio, mirror_num, bio_flags);
 	return ret;
@@ -3347,7 +3398,7 @@ static int __extent_writepage(struct page *page, struct writeback_control *wbc,
 						 sector, iosize, pg_offset,
 						 bdev, &epd->bio, max_nr,
 						 end_bio_extent_writepage,
-						 0, 0, 0);
+						 0, 0, 0, false);
 			if (ret)
 				SetPageError(page);
 		}
@@ -3516,7 +3567,7 @@ static int write_one_eb(struct extent_buffer *eb,
 		ret = submit_extent_page(rw, tree, p, offset >> 9,
 					 PAGE_CACHE_SIZE, 0, bdev, &epd->bio,
 					 -1, end_bio_extent_buffer_writepage,
-					 0, epd->bio_flags, bio_flags);
+					 0, epd->bio_flags, bio_flags, false);
 		epd->bio_flags = bio_flags;
 		if (ret) {
 			set_bit(EXTENT_BUFFER_IOERR, &eb->bflags);
@@ -3918,6 +3969,7 @@ int extent_readpages(struct extent_io_tree *tree,
 	struct page *page;
 	struct extent_map *em_cached = NULL;
 	int nr = 0;
+	u64 prev_em_start = (u64)-1;
 
 	for (page_idx = 0; page_idx < nr_pages; page_idx++) {
 		page = list_entry(pages->prev, struct page, lru);
@@ -3934,12 +3986,12 @@ int extent_readpages(struct extent_io_tree *tree,
 		if (nr < ARRAY_SIZE(pagepool))
 			continue;
 		__extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
-				   &bio, 0, &bio_flags, READ);
+				   &bio, 0, &bio_flags, READ, &prev_em_start);
 		nr = 0;
 	}
 	if (nr)
 		__extent_readpages(tree, pagepool, nr, get_extent, &em_cached,
-				   &bio, 0, &bio_flags, READ);
+				   &bio, 0, &bio_flags, READ, &prev_em_start);
 
 	if (em_cached)
 		free_extent_map(em_cached);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 653cdd85e0f2..eaf8699ed559 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -4668,7 +4668,8 @@ void btrfs_evict_inode(struct inode *inode)
 		goto no_delete;
 	}
 	/* do we really want it for ->i_nlink > 0 and zero btrfs_root_refs? */
-	btrfs_wait_ordered_range(inode, 0, (u64)-1);
+	if (!special_file(inode->i_mode))
+		btrfs_wait_ordered_range(inode, 0, (u64)-1);
 
 	if (root->fs_info->log_root_recovering) {
 		BUG_ON(test_bit(BTRFS_INODE_HAS_ORPHAN_ITEM,
diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 4934347321d3..3299778391fd 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -441,6 +441,48 @@ find_domain_name(struct cifs_ses *ses, const struct nls_table *nls_cp)
 	return 0;
 }
 
+/* Server has provided av pairs/target info in the type 2 challenge
+ * packet and we have plucked it and stored within smb session.
+ * We parse that blob here to find the server given timestamp
+ * as part of ntlmv2 authentication (or local current time as
+ * default in case of failure)
+ */
+static __le64
+find_timestamp(struct cifs_ses *ses)
+{
+	unsigned int attrsize;
+	unsigned int type;
+	unsigned int onesize = sizeof(struct ntlmssp2_name);
+	unsigned char *blobptr;
+	unsigned char *blobend;
+	struct ntlmssp2_name *attrptr;
+
+	if (!ses->auth_key.len || !ses->auth_key.response)
+		return 0;
+
+	blobptr = ses->auth_key.response;
+	blobend = blobptr + ses->auth_key.len;
+
+	while (blobptr + onesize < blobend) {
+		attrptr = (struct ntlmssp2_name *) blobptr;
+		type = le16_to_cpu(attrptr->type);
+		if (type == NTLMSSP_AV_EOL)
+			break;
+		blobptr += 2; /* advance attr type */
+		attrsize = le16_to_cpu(attrptr->length);
+		blobptr += 2; /* advance attr size */
+		if (blobptr + attrsize > blobend)
+			break;
+		if (type == NTLMSSP_AV_TIMESTAMP) {
+			if (attrsize == sizeof(u64))
+				return *((__le64 *)blobptr);
+		}
+		blobptr += attrsize; /* advance attr value */
+	}
+
+	return cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
+}
+
 static int calc_ntlmv2_hash(struct cifs_ses *ses, char *ntlmv2_hash,
 			    const struct nls_table *nls_cp)
 {
@@ -637,6 +679,7 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
 	struct ntlmv2_resp *ntlmv2;
 	char ntlmv2_hash[16];
 	unsigned char *tiblob = NULL; /* target info blob */
+	__le64 rsp_timestamp;
 
 	if (ses->server->negflavor == CIFS_NEGFLAVOR_EXTENDED) {
 		if (!ses->domainName) {
@@ -655,6 +698,12 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
 		}
 	}
 
+	/* Must be within 5 minutes of the server (or in range +/-2h
+	 * in case of Mac OS X), so simply carry over server timestamp
+	 * (as Windows 7 does)
+	 */
+	rsp_timestamp = find_timestamp(ses);
+
 	baselen = CIFS_SESS_KEY_SIZE + sizeof(struct ntlmv2_resp);
 	tilen = ses->auth_key.len;
 	tiblob = ses->auth_key.response;
@@ -671,8 +720,8 @@ setup_ntlmv2_rsp(struct cifs_ses *ses, const struct nls_table *nls_cp)
 			(ses->auth_key.response + CIFS_SESS_KEY_SIZE);
 	ntlmv2->blob_signature = cpu_to_le32(0x00000101);
 	ntlmv2->reserved = 0;
-	/* Must be within 5 minutes of the server */
-	ntlmv2->time = cpu_to_le64(cifs_UnixTimeToNT(CURRENT_TIME));
+	ntlmv2->time = rsp_timestamp;
+
 	get_random_bytes(&ntlmv2->client_chal, sizeof(ntlmv2->client_chal));
 	ntlmv2->reserved2 = 0;
 
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 30f3eb5bc022..6aeb1de0fa23 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -49,9 +49,13 @@ change_conf(struct TCP_Server_Info *server)
 		break;
 	default:
 		server->echoes = true;
-		server->oplocks = true;
+		if (enable_oplocks) {
+			server->oplocks = true;
+			server->oplock_credits = 1;
+		} else
+			server->oplocks = false;
+
 		server->echo_credits = 1;
-		server->oplock_credits = 1;
 	}
 	server->credits -= server->echo_credits + server->oplock_credits;
 	return 0;
diff --git a/fs/dcache.c b/fs/dcache.c
index 02558cb36042..15bc5f602be1 100644
--- a/fs/dcache.c
+++ b/fs/dcache.c
@@ -2819,6 +2819,13 @@ restart:
 
 		if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) {
 			struct mount *parent = ACCESS_ONCE(mnt->mnt_parent);
+			/* Escaped? */
+			if (dentry != vfsmnt->mnt_root) {
+				bptr = *buffer;
+				blen = *buflen;
+				error = 3;
+				break;
+			}
 			/* Global root? */
 			if (mnt != parent) {
 				dentry = ACCESS_ONCE(mnt->mnt_mountpoint);
diff --git a/fs/jbd2/checkpoint.c b/fs/jbd2/checkpoint.c
index b892355f1944..d4c7e470dec8 100644
--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -475,14 +475,15 @@ int jbd2_cleanup_journal_tail(journal_t *journal)
  * journal_clean_one_cp_list
  *
  * Find all the written-back checkpoint buffers in the given list and
- * release them.
+ * release them. If 'destroy' is set, clean all buffers unconditionally.
  *
  * Called with the journal locked.
  * Called with j_list_lock held.
  * Returns number of buffers reaped (for debug)
  */
 
-static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
+static int journal_clean_one_cp_list(struct journal_head *jh, bool destroy,
+				     int *released)
 {
 	struct journal_head *last_jh;
 	struct journal_head *next_jh = jh;
@@ -496,7 +497,10 @@ static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
 	do {
 		jh = next_jh;
 		next_jh = jh->b_cpnext;
-		ret = __try_to_free_cp_buf(jh);
+		if (!destroy)
+			ret = __try_to_free_cp_buf(jh);
+		else
+			ret = __jbd2_journal_remove_checkpoint(jh) + 1;
 		if (ret) {
 			freed++;
 			if (ret == 2) {
@@ -521,13 +525,14 @@ static int journal_clean_one_cp_list(struct journal_head *jh, int *released)
  * journal_clean_checkpoint_list
  *
  * Find all the written-back checkpoint buffers in the journal and release them.
+ * If 'destroy' is set, release all buffers unconditionally.
  *
  * Called with the journal locked.
  * Called with j_list_lock held.
  * Returns number of buffers reaped (for debug)
  */
 
-int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
+int __jbd2_journal_clean_checkpoint_list(journal_t *journal, bool destroy)
 {
 	transaction_t *transaction, *last_transaction, *next_transaction;
 	int ret = 0;
@@ -543,7 +548,7 @@ int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
 		transaction = next_transaction;
 		next_transaction = transaction->t_cpnext;
 		ret += journal_clean_one_cp_list(transaction->
-				t_checkpoint_list, &released);
+				t_checkpoint_list, destroy, &released);
 		/*
 		 * This function only frees up some memory if possible so we
 		 * dont have an obligation to finish processing. Bail out if
@@ -559,7 +564,7 @@ int __jbd2_journal_clean_checkpoint_list(journal_t *journal)
 		 * we can possibly see not yet submitted buffers on io_list
 		 */
 		ret += journal_clean_one_cp_list(transaction->
-				t_checkpoint_io_list, &released);
+				t_checkpoint_io_list, destroy, &released);
 		if (need_resched())
 			goto out;
 	} while (transaction != last_transaction);
@@ -568,6 +573,28 @@ out:
 }
 
 /*
+ * Remove buffers from all checkpoint lists as journal is aborted and we just
+ * need to free memory
+ */
+void jbd2_journal_destroy_checkpoint(journal_t *journal)
+{
+	/*
+	 * We loop because __jbd2_journal_clean_checkpoint_list() may abort
+	 * early due to a need of rescheduling.
+	 */
+	while (1) {
+		spin_lock(&journal->j_list_lock);
+		if (!journal->j_checkpoint_transactions) {
+			spin_unlock(&journal->j_list_lock);
+			break;
+		}
+		__jbd2_journal_clean_checkpoint_list(journal, true);
+		spin_unlock(&journal->j_list_lock);
+		cond_resched();
+	}
+}
+
+/*
  * journal_remove_checkpoint: called after a buffer has been committed
  * to disk (either by being write-back flushed to disk, or being
  * committed to the log).
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 9181c2b22b3c..4207cf2caa87 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -510,7 +510,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
 	 * frees some memory
 	 */
 	spin_lock(&journal->j_list_lock);
-	__jbd2_journal_clean_checkpoint_list(journal);
+	__jbd2_journal_clean_checkpoint_list(journal, false);
 	spin_unlock(&journal->j_list_lock);
 
 	jbd_debug(3, "JBD2: commit phase 1\n");
diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c
index e8d62d742435..3b607a8609c4 100644
--- a/fs/jbd2/journal.c
+++ b/fs/jbd2/journal.c
@@ -1708,8 +1708,17 @@ int jbd2_journal_destroy(journal_t *journal)
 	while (journal->j_checkpoint_transactions != NULL) {
 		spin_unlock(&journal->j_list_lock);
 		mutex_lock(&journal->j_checkpoint_mutex);
-		jbd2_log_do_checkpoint(journal);
+		err = jbd2_log_do_checkpoint(journal);
 		mutex_unlock(&journal->j_checkpoint_mutex);
+		/*
+		 * If checkpointing failed, just free the buffers to avoid
+		 * looping forever
+		 */
+		if (err) {
+			jbd2_journal_destroy_checkpoint(journal);
+			spin_lock(&journal->j_list_lock);
+			break;
+		}
 		spin_lock(&journal->j_list_lock);
 	}
 
diff --git a/fs/namei.c b/fs/namei.c
index 5df3b6ed4594..40663e2d130c 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -485,6 +485,24 @@ void path_put(const struct path *path)
 }
 EXPORT_SYMBOL(path_put);
 
+/**
+ * path_connected - Verify that a path->dentry is below path->mnt.mnt_root
+ * @path: nameidate to verify
+ *
+ * Rename can sometimes move a file or directory outside of a bind
+ * mount, path_connected allows those cases to be detected.
+ */
+static bool path_connected(const struct path *path)
+{
+	struct vfsmount *mnt = path->mnt;
+
+	/* Only bind mounts can have disconnected paths */
+	if (mnt->mnt_root == mnt->mnt_sb->s_root)
+		return true;
+
+	return is_subdir(path->dentry, mnt->mnt_root);
+}
+
 /*
  * Path walking has 2 modes, rcu-walk and ref-walk (see
  * Documentation/filesystems/path-lookup.txt).  In situations when we can't
@@ -1150,6 +1168,8 @@ static int follow_dotdot_rcu(struct nameidata *nd)
 				goto failed;
 			nd->path.dentry = parent;
 			nd->seq = seq;
+			if (unlikely(!path_connected(&nd->path)))
+				goto failed;
 			break;
 		}
 		if (!follow_up_rcu(&nd->path))
@@ -1243,7 +1263,7 @@ static void follow_mount(struct path *path)
 	}
 }
 
-static void follow_dotdot(struct nameidata *nd)
+static int follow_dotdot(struct nameidata *nd)
 {
 	if (!nd->root.mnt)
 		set_root(nd);
@@ -1259,6 +1279,10 @@ static void follow_dotdot(struct nameidata *nd)
 			/* rare case of legitimate dget_parent()... */
 			nd->path.dentry = dget_parent(nd->path.dentry);
 			dput(old);
+			if (unlikely(!path_connected(&nd->path))) {
+				path_put(&nd->path);
+				return -ENOENT;
+			}
 			break;
 		}
 		if (!follow_up(&nd->path))
@@ -1266,6 +1290,7 @@ static void follow_dotdot(struct nameidata *nd)
 	}
 	follow_mount(&nd->path);
 	nd->inode = nd->path.dentry->d_inode;
+	return 0;
 }
 
 /*
@@ -1489,7 +1514,7 @@ static inline int handle_dots(struct nameidata *nd, int type)
 			if (follow_dotdot_rcu(nd))
 				return -ECHILD;
 		} else
-			follow_dotdot(nd);
+			return follow_dotdot(nd);
 	}
 	return 0;
 }
@@ -2215,7 +2240,7 @@ mountpoint_last(struct nameidata *nd, struct path *path)
 	if (unlikely(nd->last_type != LAST_NORM)) {
 		error = handle_dots(nd, nd->last_type);
 		if (error)
-			goto out;
+			return error;
 		dentry = dget(nd->path.dentry);
 		goto done;
 	}