23 files changed, 270 insertions, 79 deletions

diff --git a/fs/Kconfig b/fs/Kconfig
index aa4c12282301..da524c4d7b7e 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -203,7 +203,7 @@ config TMPFS_XATTR
 
 config TMPFS_INODE64
 	bool "Use 64-bit ino_t by default in tmpfs"
-	depends on TMPFS && 64BIT
+	depends on TMPFS && 64BIT && !(S390 || ALPHA)
 	default n
 	help
 	  tmpfs has historically used only inode numbers as wide as an unsigned
diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
index 68900f1629bf..97ac363b5df1 100644
--- a/fs/cifs/dir.c
+++ b/fs/cifs/dir.c
@@ -737,6 +737,7 @@ static int
 cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
 {
 	struct inode *inode;
+	int rc;
 
 	if (flags & LOOKUP_RCU)
 		return -ECHILD;
@@ -746,8 +747,25 @@ cifs_d_revalidate(struct dentry *direntry, unsigned int flags)
 		if ((flags & LOOKUP_REVAL) && !CIFS_CACHE_READ(CIFS_I(inode)))
 			CIFS_I(inode)->time = 0; /* force reval */
 
-		if (cifs_revalidate_dentry(direntry))
-			return 0;
+		rc = cifs_revalidate_dentry(direntry);
+		if (rc) {
+			cifs_dbg(FYI, "cifs_revalidate_dentry failed with rc=%d", rc);
+			switch (rc) {
+			case -ENOENT:
+			case -ESTALE:
+				/*
+				 * Those errors mean the dentry is invalid
+				 * (file was deleted or recreated)
+				 */
+				return 0;
+			default:
+				/*
+				 * Otherwise some unexpected error happened
+				 * report it as-is to VFS layer
+				 */
+				return rc;
+			}
+		}
 		else {
 			/*
 			 * If the inode wasn't known to be a dfs entry when
diff --git a/fs/cifs/smb2pdu.h b/fs/cifs/smb2pdu.h
index d85edf5d1429..a5a9e33c0d73 100644
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -286,7 +286,7 @@ struct smb2_negotiate_req {
 	__le32 NegotiateContextOffset; /* SMB3.1.1 only. MBZ earlier */
 	__le16 NegotiateContextCount;  /* SMB3.1.1 only. MBZ earlier */
 	__le16 Reserved2;
-	__le16 Dialects[1]; /* One dialect (vers=) at a time for now */
+	__le16 Dialects[4]; /* BB expand this if autonegotiate > 4 dialects */
 } __packed;
 
 /* Dialects */
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index 95ef26b555b9..4a2b836eb017 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -666,10 +666,22 @@ wait_for_compound_request(struct TCP_Server_Info *server, int num,
 
 	if (*credits < num) {
 		/*
-		 * Return immediately if not too many requests in flight since
-		 * we will likely be stuck on waiting for credits.
+		 * If the server is tight on resources or just gives us less
+		 * credits for other reasons (e.g. requests are coming out of
+		 * order and the server delays granting more credits until it
+		 * processes a missing mid) and we exhausted most available
+		 * credits there may be situations when we try to send
+		 * a compound request but we don't have enough credits. At this
+		 * point the client needs to decide if it should wait for
+		 * additional credits or fail the request. If at least one
+		 * request is in flight there is a high probability that the
+		 * server will return enough credits to satisfy this compound
+		 * request.
+		 *
+		 * Return immediately if no requests in flight since we will be
+		 * stuck on waiting for credits.
 		 */
-		if (server->in_flight < num - *credits) {
+		if (server->in_flight == 0) {
 			spin_unlock(&server->req_lock);
 			trace_smb3_insufficient_credits(server->CurrentMid,
 					server->hostname, scredits, sin_flight);
diff --git a/fs/hugetlbfs/inode.c b/fs/hugetlbfs/inode.c
index b5c109703daa..21c20fd5f9ee 100644
--- a/fs/hugetlbfs/inode.c
+++ b/fs/hugetlbfs/inode.c
@@ -735,9 +735,10 @@ static long hugetlbfs_fallocate(struct file *file, int mode, loff_t offset,
 
 		mutex_unlock(&hugetlb_fault_mutex_table[hash]);
 
+		set_page_huge_active(page);
 		/*
 		 * unlock_page because locked by add_to_page_cache()
-		 * page_put due to reference from alloc_huge_page()
+		 * put_page() due to reference from alloc_huge_page()
 		 */
 		unlock_page(page);
 		put_page(page);
diff --git a/fs/io_uring.c b/fs/io_uring.c
index 38c6cbe1ab38..1f68105a41ed 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2205,6 +2205,9 @@ static void __io_req_task_submit(struct io_kiocb *req)
 	else
 		__io_req_task_cancel(req, -EFAULT);
 	mutex_unlock(&ctx->uring_lock);
+
+	if (ctx->flags & IORING_SETUP_SQPOLL)
+		io_sq_thread_drop_mm_files();
 }
 
 static void io_req_task_submit(struct callback_head *cb)
@@ -8982,12 +8985,6 @@ static void io_uring_cancel_task_requests(struct io_ring_ctx *ctx,
 
 	if ((ctx->flags & IORING_SETUP_SQPOLL) && ctx->sq_data) {
 		atomic_dec(&task->io_uring->in_idle);
-		/*
-		 * If the files that are going away are the ones in the thread
-		 * identity, clear them out.
-		 */
-		if (task->io_uring->identity->files == files)
-			task->io_uring->identity->files = NULL;
 		io_sq_thread_unpark(ctx->sq_data);
 	}
 }
diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 64bc81363c6c..e1bd592ce700 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -141,6 +141,7 @@ const struct file_operations nilfs_file_operations = {
 	/* .release	= nilfs_release_file, */
 	.fsync		= nilfs_sync_file,
 	.splice_read	= generic_file_splice_read,
+	.splice_write   = iter_file_splice_write,
 };
 
 const struct inode_operations nilfs_file_inode_operations = {
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index e5b616c93e11..0fed532efa68 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -84,6 +84,14 @@ int ovl_copy_xattr(struct super_block *sb, struct dentry *old,
 
 		if (ovl_is_private_xattr(sb, name))
 			continue;
+
+		error = security_inode_copy_up_xattr(name);
+		if (error < 0 && error != -EOPNOTSUPP)
+			break;
+		if (error == 1) {
+			error = 0;
+			continue; /* Discard */
+		}
 retry:
 		size = vfs_getxattr(old, name, value, value_size);
 		if (size == -ERANGE)
@@ -107,13 +115,6 @@ retry:
 			goto retry;
 		}
 
-		error = security_inode_copy_up_xattr(name);
-		if (error < 0 && error != -EOPNOTSUPP)
-			break;
-		if (error == 1) {
-			error = 0;
-			continue; /* Discard */
-		}
 		error = vfs_setxattr(new, name, value, size, 0);
 		if (error) {
 			if (error != -EOPNOTSUPP || ovl_must_copy_xattr(name))
diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index 28a075b5f5b2..d1efa3a5a503 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -992,8 +992,8 @@ static char *ovl_get_redirect(struct dentry *dentry, bool abs_redirect)
 
 		buflen -= thislen;
 		memcpy(&buf[buflen], name, thislen);
-		tmp = dget_dlock(d->d_parent);
 		spin_unlock(&d->d_lock);
+		tmp = dget_parent(d);
 
 		dput(d);
 		d = tmp;
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index bd9dd38347ae..077d3ad343f6 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -398,8 +398,9 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
 	const struct cred *old_cred;
 	int ret;
 
-	if (!ovl_should_sync(OVL_FS(file_inode(file)->i_sb)))
-		return 0;
+	ret = ovl_sync_status(OVL_FS(file_inode(file)->i_sb));
+	if (ret <= 0)
+		return ret;
 
 	ret = ovl_real_fdget_meta(file, &real, !datasync);
 	if (ret)
diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index d739e14c6814..cf41bcb664bc 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -352,7 +352,9 @@ int ovl_xattr_set(struct dentry *dentry, struct inode *inode, const char *name,
 		goto out;
 
 	if (!value && !upperdentry) {
+		old_cred = ovl_override_creds(dentry->d_sb);
 		err = vfs_getxattr(realdentry, name, NULL, 0);
+		revert_creds(old_cred);
 		if (err < 0)
 			goto out_drop_write;
 	}
diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index b487e48c7fd4..cb4e2d60ecf9 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -324,6 +324,7 @@ int ovl_check_metacopy_xattr(struct ovl_fs *ofs, struct dentry *dentry);
 bool ovl_is_metacopy_dentry(struct dentry *dentry);
 char *ovl_get_redirect_xattr(struct ovl_fs *ofs, struct dentry *dentry,
 			     int padding);
+int ovl_sync_status(struct ovl_fs *ofs);
 
 static inline bool ovl_is_impuredir(struct super_block *sb,
 				    struct dentry *dentry)
diff --git a/fs/overlayfs/ovl_entry.h b/fs/overlayfs/ovl_entry.h
index fbd5e27ce66b..63efee554f69 100644
--- a/fs/overlayfs/ovl_entry.h
+++ b/fs/overlayfs/ovl_entry.h
@@ -81,6 +81,8 @@ struct ovl_fs {
 	atomic_long_t last_ino;
 	/* Whiteout dentry cache */
 	struct dentry *whiteout;
+	/* r/o snapshot of upperdir sb's only taken on volatile mounts */
+	errseq_t errseq;
 };
 
 static inline struct vfsmount *ovl_upper_mnt(struct ovl_fs *ofs)
diff --git a/fs/overlayfs/readdir.c b/fs/overlayfs/readdir.c
index 01620ebae1bd..f404a78e6b60 100644
--- a/fs/overlayfs/readdir.c
+++ b/fs/overlayfs/readdir.c
@@ -865,7 +865,7 @@ struct file *ovl_dir_real_file(const struct file *file, bool want_upper)
 
 	struct ovl_dir_file *od = file->private_data;
 	struct dentry *dentry = file->f_path.dentry;
-	struct file *realfile = od->realfile;
+	struct file *old, *realfile = od->realfile;
 
 	if (!OVL_TYPE_UPPER(ovl_path_type(dentry)))
 		return want_upper ? NULL : realfile;
@@ -874,29 +874,20 @@ struct file *ovl_dir_real_file(const struct file *file, bool want_upper)
 	 * Need to check if we started out being a lower dir, but got copied up
 	 */
 	if (!od->is_upper) {
-		struct inode *inode = file_inode(file);
-
 		realfile = READ_ONCE(od->upperfile);
 		if (!realfile) {
 			struct path upperpath;
 
 			ovl_path_upper(dentry, &upperpath);
 			realfile = ovl_dir_open_realfile(file, &upperpath);
+			if (IS_ERR(realfile))
+				return realfile;
 
-			inode_lock(inode);
-			if (!od->upperfile) {
-				if (IS_ERR(realfile)) {
-					inode_unlock(inode);
-					return realfile;
-				}
-				smp_store_release(&od->upperfile, realfile);
-			} else {
-				/* somebody has beaten us to it */
-				if (!IS_ERR(realfile))
-					fput(realfile);
-				realfile = od->upperfile;
+			old = cmpxchg_release(&od->upperfile, NULL, realfile);
+			if (old) {
+				fput(realfile);
+				realfile = old;
 			}
-			inode_unlock(inode);
 		}
 	}
 
@@ -909,8 +900,9 @@ static int ovl_dir_fsync(struct file *file, loff_t start, loff_t end,
 	struct file *realfile;
 	int err;
 
-	if (!ovl_should_sync(OVL_FS(file->f_path.dentry->d_sb)))
-		return 0;
+	err = ovl_sync_status(OVL_FS(file->f_path.dentry->d_sb));
+	if (err <= 0)
+		return err;
 
 	realfile = ovl_dir_real_file(file, true);
 	err = PTR_ERR_OR_ZERO(realfile);
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index 2bd570cbe8a4..d58b8f2bf9d0 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -264,11 +264,20 @@ static int ovl_sync_fs(struct super_block *sb, int wait)
 	struct super_block *upper_sb;
 	int ret;
 
-	if (!ovl_upper_mnt(ofs))
-		return 0;
+	ret = ovl_sync_status(ofs);
+	/*
+	 * We have to always set the err, because the return value isn't
+	 * checked in syncfs, and instead indirectly return an error via
+	 * the sb's writeback errseq, which VFS inspects after this call.
+	 */
+	if (ret < 0) {
+		errseq_set(&sb->s_wb_err, -EIO);
+		return -EIO;
+	}
+
+	if (!ret)
+		return ret;
 
-	if (!ovl_should_sync(ofs))
-		return 0;
 	/*
 	 * Not called for sync(2) call or an emergency sync (SB_I_SKIP_SYNC).
 	 * All the super blocks will be iterated, including upper_sb.
@@ -1923,6 +1932,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 	unsigned int numlower;
 	int err;
 
+	err = -EIO;
+	if (WARN_ON(sb->s_user_ns != current_user_ns()))
+		goto out;
+
 	sb->s_d_op = &ovl_dentry_operations;
 
 	err = -ENOMEM;
@@ -1989,6 +2002,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 	sb->s_op = &ovl_super_operations;
 
 	if (ofs->config.upperdir) {
+		struct super_block *upper_sb;
+
 		if (!ofs->config.workdir) {
 			pr_err("missing 'workdir'\n");
 			goto out_err;
@@ -1998,6 +2013,16 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 		if (err)
 			goto out_err;
 
+		upper_sb = ovl_upper_mnt(ofs)->mnt_sb;
+		if (!ovl_should_sync(ofs)) {
+			ofs->errseq = errseq_sample(&upper_sb->s_wb_err);
+			if (errseq_check(&upper_sb->s_wb_err, ofs->errseq)) {
+				err = -EIO;
+				pr_err("Cannot mount volatile when upperdir has an unseen error. Sync upperdir fs to clear state.\n");
+				goto out_err;
+			}
+		}
+
 		err = ovl_get_workdir(sb, ofs, &upperpath);
 		if (err)
 			goto out_err;
@@ -2005,9 +2030,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
 		if (!ofs->workdir)
 			sb->s_flags |= SB_RDONLY;
 
-		sb->s_stack_depth = ovl_upper_mnt(ofs)->mnt_sb->s_stack_depth;
-		sb->s_time_gran = ovl_upper_mnt(ofs)->mnt_sb->s_time_gran;
-
+		sb->s_stack_depth = upper_sb->s_stack_depth;
+		sb->s_time_gran = upper_sb->s_time_gran;
 	}
 	oe = ovl_get_lowerstack(sb, splitlower, numlower, ofs, layers);
 	err = PTR_ERR(oe);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 6569031af3cd..9826b003f1d2 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -962,3 +962,30 @@ err_free:
 	kfree(buf);
 	return ERR_PTR(res);
 }
+
+/*
+ * ovl_sync_status() - Check fs sync status for volatile mounts
+ *
+ * Returns 1 if this is not a volatile mount and a real sync is required.
+ *
+ * Returns 0 if syncing can be skipped because mount is volatile, and no errors
+ * have occurred on the upperdir since the mount.
+ *
+ * Returns -errno if it is a volatile mount, and the error that occurred since
+ * the last mount. If the error code changes, it'll return the latest error
+ * code.
+ */
+
+int ovl_sync_status(struct ovl_fs *ofs)
+{
+	struct vfsmount *mnt;
+
+	if (ovl_should_sync(ofs))
+		return 1;
+
+	mnt = ovl_upper_mnt(ofs);
+	if (!mnt)
+		return 0;
+
+	return errseq_check(&mnt->mnt_sb->s_wb_err, ofs->errseq);
+}
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 8a19773b5a0b..45f44425d856 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -196,9 +196,15 @@ int squashfs_read_data(struct super_block *sb, u64 index, int length,
 		length = SQUASHFS_COMPRESSED_SIZE(length);
 		index += 2;
 
-		TRACE("Block @ 0x%llx, %scompressed size %d\n", index,
+		TRACE("Block @ 0x%llx, %scompressed size %d\n", index - 2,
 		      compressed ? "" : "un", length);
 	}
+	if (length < 0 || length > output->length ||
+			(index + length) > msblk->bytes_used) {
+		res = -EIO;
+		goto out;
+	}
+
 	if (next_index)
 		*next_index = index + length;
 
diff --git a/fs/squashfs/export.c b/fs/squashfs/export.c
index ae2c87bb0fbe..eb02072d28dd 100644
--- a/fs/squashfs/export.c
+++ b/fs/squashfs/export.c
@@ -41,12 +41,17 @@ static long long squashfs_inode_lookup(struct super_block *sb, int ino_num)
 	struct squashfs_sb_info *msblk = sb->s_fs_info;
 	int blk = SQUASHFS_LOOKUP_BLOCK(ino_num - 1);
 	int offset = SQUASHFS_LOOKUP_BLOCK_OFFSET(ino_num - 1);
-	u64 start = le64_to_cpu(msblk->inode_lookup_table[blk]);
+	u64 start;
 	__le64 ino;
 	int err;
 
 	TRACE("Entered squashfs_inode_lookup, inode_number = %d\n", ino_num);
 
+	if (ino_num == 0 || (ino_num - 1) >= msblk->inodes)
+		return -EINVAL;
+
+	start = le64_to_cpu(msblk->inode_lookup_table[blk]);
+
 	err = squashfs_read_metadata(sb, &ino, &start, &offset, sizeof(ino));
 	if (err < 0)
 		return err;
@@ -111,7 +116,10 @@ __le64 *squashfs_read_inode_lookup_table(struct super_block *sb,
 		u64 lookup_table_start, u64 next_table, unsigned int inodes)
 {
 	unsigned int length = SQUASHFS_LOOKUP_BLOCK_BYTES(inodes);
+	unsigned int indexes = SQUASHFS_LOOKUP_BLOCKS(inodes);
+	int n;
 	__le64 *table;
+	u64 start, end;
 
 	TRACE("In read_inode_lookup_table, length %d\n", length);
 
@@ -121,20 +129,37 @@ __le64 *squashfs_read_inode_lookup_table(struct super_block *sb,
 	if (inodes == 0)
 		return ERR_PTR(-EINVAL);
 
-	/* length bytes should not extend into the next table - this check
-	 * also traps instances where lookup_table_start is incorrectly larger
-	 * than the next table start
+	/*
+	 * The computed size of the lookup table (length bytes) should exactly
+	 * match the table start and end points
 	 */
-	if (lookup_table_start + length > next_table)
+	if (length != (next_table - lookup_table_start))
 		return ERR_PTR(-EINVAL);
 
 	table = squashfs_read_table(sb, lookup_table_start, length);
+	if (IS_ERR(table))
+		return table;
 
 	/*
-	 * table[0] points to the first inode lookup table metadata block,
-	 * this should be less than lookup_table_start
+	 * table0], table[1], ... table[indexes - 1] store the locations
+	 * of the compressed inode lookup blocks.  Each entry should be
+	 * less than the next (i.e. table[0] < table[1]), and the difference
+	 * between them should be SQUASHFS_METADATA_SIZE or less.
+	 * table[indexes - 1] should  be less than lookup_table_start, and
+	 * again the difference should be SQUASHFS_METADATA_SIZE or less
 	 */
-	if (!IS_ERR(table) && le64_to_cpu(table[0]) >= lookup_table_start) {
+	for (n = 0; n < (indexes - 1); n++) {
+		start = le64_to_cpu(table[n]);
+		end = le64_to_cpu(table[n + 1]);
+
+		if (start >= end || (end - start) > SQUASHFS_METADATA_SIZE) {
+			kfree(table);
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	start = le64_to_cpu(table[indexes - 1]);
+	if (start >= lookup_table_start || (lookup_table_start - start) > SQUASHFS_METADATA_SIZE) {
 		kfree(table);
 		return ERR_PTR(-EINVAL);
 	}
diff --git a/fs/squashfs/id.c b/fs/squashfs/id.c
index 6be5afe7287d..11581bf31af4 100644
--- a/fs/squashfs/id.c
+++ b/fs/squashfs/id.c
@@ -35,10 +35,15 @@ int squashfs_get_id(struct super_block *sb, unsigned int index,
 	struct squashfs_sb_info *msblk = sb->s_fs_info;
 	int block = SQUASHFS_ID_BLOCK(index);
 	int offset = SQUASHFS_ID_BLOCK_OFFSET(index);
-	u64 start_block = le64_to_cpu(msblk->id_table[block]);
+	u64 start_block;
 	__le32 disk_id;
 	int err;
 
+	if (index >= msblk->ids)
+		return -EINVAL;
+
+	start_block = le64_to_cpu(msblk->id_table[block]);
+
 	err = squashfs_read_metadata(sb, &disk_id, &start_block, &offset,
 							sizeof(disk_id));
 	if (err < 0)
@@ -56,7 +61,10 @@ __le64 *squashfs_read_id_index_table(struct super_block *sb,
 		u64 id_table_start, u64 next_table, unsigned short no_ids)
 {
 	unsigned int length = SQUASHFS_ID_BLOCK_BYTES(no_ids);
+	unsigned int indexes = SQUASHFS_ID_BLOCKS(no_ids);
+	int n;
 	__le64 *table;
+	u64 start, end;
 
 	TRACE("In read_id_index_table, length %d\n", length);
 
@@ -67,20 +75,36 @@ __le64 *squashfs_read_id_index_table(struct super_block *sb,
 		return ERR_PTR(-EINVAL);
 
 	/*
-	 * length bytes should not extend into the next table - this check
-	 * also traps instances where id_table_start is incorrectly larger
-	 * than the next table start
+	 * The computed size of the index table (length bytes) should exactly
+	 * match the table start and end points
 	 */
-	if (id_table_start + length > next_table)
+	if (length != (next_table - id_table_start))
 		return ERR_PTR(-EINVAL);
 
 	table = squashfs_read_table(sb, id_table_start, length);
+	if (IS_ERR(table))
+		return table;
 
 	/*
-	 * table[0] points to the first id lookup table metadata block, this
-	 * should be less than id_table_start
+	 * table[0], table[1], ... table[indexes - 1] store the locations
+	 * of the compressed id blocks.   Each entry should be less than
+	 * the next (i.e. table[0] < table[1]), and the difference between them
+	 * should be SQUASHFS_METADATA_SIZE or less.  table[indexes - 1]
+	 * should be less than id_table_start, and again the difference
+	 * should be SQUASHFS_METADATA_SIZE or less
 	 */
-	if (!IS_ERR(table) && le64_to_cpu(table[0]) >= id_table_start) {
+	for (n = 0; n < (indexes - 1); n++) {
+		start = le64_to_cpu(table[n]);
+		end = le64_to_cpu(table[n + 1]);
+
+		if (start >= end || (end - start) > SQUASHFS_METADATA_SIZE) {
+			kfree(table);
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	start = le64_to_cpu(table[indexes - 1]);
+	if (start >= id_table_start || (id_table_start - start) > SQUASHFS_METADATA_SIZE) {
 		kfree(table);
 		return ERR_PTR(-EINVAL);
 	}
diff --git a/fs/squashfs/squashfs_fs_sb.h b/fs/squashfs/squashfs_fs_sb.h
index 34c21ffb6df3..166e98806265 100644
--- a/fs/squashfs/squashfs_fs_sb.h
+++ b/fs/squashfs/squashfs_fs_sb.h
@@ -64,5 +64,6 @@ struct squashfs_sb_info {
 	unsigned int				inodes;
 	unsigned int				fragments;
 	int					xattr_ids;
+	unsigned int				ids;
 };
 #endif
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index d6c6593ec169..88cc94be1076 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -166,6 +166,7 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
 	msblk->directory_table = le64_to_cpu(sblk->directory_table_start);
 	msblk->inodes = le32_to_cpu(sblk->inodes);
 	msblk->fragments = le32_to_cpu(sblk->fragments);
+	msblk->ids = le16_to_cpu(sblk->no_ids);
 	flags = le16_to_cpu(sblk->flags);
 
 	TRACE("Found valid superblock on %pg\n", sb->s_bdev);
@@ -177,7 +178,7 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
 	TRACE("Block size %d\n", msblk->block_size);
 	TRACE("Number of inodes %d\n", msblk->inodes);
 	TRACE("Number of fragments %d\n", msblk->fragments);
-	TRACE("Number of ids %d\n", le16_to_cpu(sblk->no_ids));
+	TRACE("Number of ids %d\n", msblk->ids);
 	TRACE("sblk->inode_table_start %llx\n", msblk->inode_table);
 	TRACE("sblk->directory_table_start %llx\n", msblk->directory_table);
 	TRACE("sblk->fragment_table_start %llx\n",
@@ -236,8 +237,7 @@ static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
 allocate_id_index_table:
 	/* Allocate and read id index table */
 	msblk->id_table = squashfs_read_id_index_table(sb,
-		le64_to_cpu(sblk->id_table_start), next_table,
-		le16_to_cpu(sblk->no_ids));
+		le64_to_cpu(sblk->id_table_start), next_table, msblk->ids);
 	if (IS_ERR(msblk->id_table)) {
 		errorf(fc, "unable to read id index table");
 		err = PTR_ERR(msblk->id_table);
diff --git a/fs/squashfs/xattr.h b/fs/squashfs/xattr.h
index 184129afd456..d8a270d3ac4c 100644
--- a/fs/squashfs/xattr.h
+++ b/fs/squashfs/xattr.h
@@ -17,8 +17,16 @@ extern int squashfs_xattr_lookup(struct super_block *, unsigned int, int *,
 static inline __le64 *squashfs_read_xattr_id_table(struct super_block *sb,
 		u64 start, u64 *xattr_table_start, int *xattr_ids)
 {
+	struct squashfs_xattr_id_table *id_table;
+
+	id_table = squashfs_read_table(sb, start, sizeof(*id_table));
+	if (IS_ERR(id_table))
+		return (__le64 *) id_table;
+
+	*xattr_table_start = le64_to_cpu(id_table->xattr_table_start);
+	kfree(id_table);
+
 	ERROR("Xattrs in filesystem, these will be ignored\n");
-	*xattr_table_start = start;
 	return ERR_PTR(-ENOTSUPP);
 }
 
diff --git a/fs/squashfs/xattr_id.c b/fs/squashfs/xattr_id.c
index d99e08464554..ead66670b41a 100644
--- a/fs/squashfs/xattr_id.c
+++ b/fs/squashfs/xattr_id.c
@@ -31,10 +31,15 @@ int squashfs_xattr_lookup(struct super_block *sb, unsigned int index,
 	struct squashfs_sb_info *msblk = sb->s_fs_info;
 	int block = SQUASHFS_XATTR_BLOCK(index);
 	int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index);
-	u64 start_block = le64_to_cpu(msblk->xattr_id_table[block]);
+	u64 start_block;
 	struct squashfs_xattr_id id;
 	int err;
 
+	if (index >= msblk->xattr_ids)
+		return -EINVAL;
+
+	start_block = le64_to_cpu(msblk->xattr_id_table[block]);
+
 	err = squashfs_read_metadata(sb, &id, &start_block, &offset,
 							sizeof(id));
 	if (err < 0)
@@ -50,13 +55,17 @@ int squashfs_xattr_lookup(struct super_block *sb, unsigned int index,
 /*
  * Read uncompressed xattr id lookup table indexes from disk into memory
  */
-__le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start,
+__le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 table_start,
 		u64 *xattr_table_start, int *xattr_ids)
 {
-	unsigned int len;
+	struct squashfs_sb_info *msblk = sb->s_fs_info;
+	unsigned int len, indexes;
 	struct squashfs_xattr_id_table *id_table;
+	__le64 *table;
+	u64 start, end;
+	int n;
 
-	id_table = squashfs_read_table(sb, start, sizeof(*id_table));
+	id_table = squashfs_read_table(sb, table_start, sizeof(*id_table));
 	if (IS_ERR(id_table))
 		return (__le64 *) id_table;
 
@@ -70,13 +79,52 @@ __le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start,
 	if (*xattr_ids == 0)
 		return ERR_PTR(-EINVAL);
 
-	/* xattr_table should be less than start */
-	if (*xattr_table_start >= start)
+	len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
+	indexes = SQUASHFS_XATTR_BLOCKS(*xattr_ids);
+
+	/*
+	 * The computed size of the index table (len bytes) should exactly
+	 * match the table start and end points
+	 */
+	start = table_start + sizeof(*id_table);
+	end = msblk->bytes_used;
+
+	if (len != (end - start))
 		return ERR_PTR(-EINVAL);
 
-	len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
+	table = squashfs_read_table(sb, start, len);
+	if (IS_ERR(table))
+		return table;
+
+	/* table[0], table[1], ... table[indexes - 1] store the locations
+	 * of the compressed xattr id blocks.  Each entry should be less than
+	 * the next (i.e. table[0] < table[1]), and the difference between them
+	 * should be SQUASHFS_METADATA_SIZE or less.  table[indexes - 1]
+	 * should be less than table_start, and again the difference
+	 * shouls be SQUASHFS_METADATA_SIZE or less.
+	 *
+	 * Finally xattr_table_start should be less than table[0].
+	 */
+	for (n = 0; n < (indexes - 1); n++) {
+		start = le64_to_cpu(table[n]);
+		end = le64_to_cpu(table[n + 1]);
+
+		if (start >= end || (end - start) > SQUASHFS_METADATA_SIZE) {
+			kfree(table);
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	start = le64_to_cpu(table[indexes - 1]);
+	if (start >= table_start || (table_start - start) > SQUASHFS_METADATA_SIZE) {
+		kfree(table);
+		return ERR_PTR(-EINVAL);
+	}
 
-	TRACE("In read_xattr_index_table, length %d\n", len);
+	if (*xattr_table_start >= le64_to_cpu(table[0])) {
+		kfree(table);
+		return ERR_PTR(-EINVAL);
+	}
 
-	return squashfs_read_table(sb, start + sizeof(*id_table), len);
+	return table;
 }