Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 473 insertions, 0 deletions

diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c
new file mode 100644
index 000000000..7adc37c10
--- /dev/null
+++ b/fs/ubifs/master.c
@@ -0,0 +1,473 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ *          Adrian Hunter
+ */
+
+/* This file implements reading and writing the master node */
+
+#include "ubifs.h"
+
+/**
+ * ubifs_compare_master_node - compare two UBIFS master nodes
+ * @c: UBIFS file-system description object
+ * @m1: the first node
+ * @m2: the second node
+ *
+ * This function compares two UBIFS master nodes. Returns 0 if they are equal
+ * and nonzero if not.
+ */
+int ubifs_compare_master_node(struct ubifs_info *c, void *m1, void *m2)
+{
+	int ret;
+	int behind;
+	int hmac_offs = offsetof(struct ubifs_mst_node, hmac);
+
+	/*
+	 * Do not compare the common node header since the sequence number and
+	 * hence the CRC are different.
+	 */
+	ret = memcmp(m1 + UBIFS_CH_SZ, m2 + UBIFS_CH_SZ,
+		     hmac_offs - UBIFS_CH_SZ);
+	if (ret)
+		return ret;
+
+	/*
+	 * Do not compare the embedded HMAC as well which also must be different
+	 * due to the different common node header.
+	 */
+	behind = hmac_offs + UBIFS_MAX_HMAC_LEN;
+
+	if (UBIFS_MST_NODE_SZ > behind)
+		return memcmp(m1 + behind, m2 + behind, UBIFS_MST_NODE_SZ - behind);
+
+	return 0;
+}
+
+/* mst_node_check_hash - Check hash of a master node
+ * @c: UBIFS file-system description object
+ * @mst: The master node
+ * @expected: The expected hash of the master node
+ *
+ * This checks the hash of a master node against a given expected hash.
+ * Note that we have two master nodes on a UBIFS image which have different
+ * sequence numbers and consequently different CRCs. To be able to match
+ * both master nodes we exclude the common node header containing the sequence
+ * number and CRC from the hash.
+ *
+ * Returns 0 if the hashes are equal, a negative error code otherwise.
+ */
+static int mst_node_check_hash(const struct ubifs_info *c,
+			       const struct ubifs_mst_node *mst,
+			       const u8 *expected)
+{
+	u8 calc[UBIFS_MAX_HASH_LEN];
+	const void *node = mst;
+
+	crypto_shash_tfm_digest(c->hash_tfm, node + sizeof(struct ubifs_ch),
+				UBIFS_MST_NODE_SZ - sizeof(struct ubifs_ch),
+				calc);
+
+	if (ubifs_check_hash(c, expected, calc))
+		return -EPERM;
+
+	return 0;
+}
+
+/**
+ * scan_for_master - search the valid master node.
+ * @c: UBIFS file-system description object
+ *
+ * This function scans the master node LEBs and search for the latest master
+ * node. Returns zero in case of success, %-EUCLEAN if there master area is
+ * corrupted and requires recovery, and a negative error code in case of
+ * failure.
+ */
+static int scan_for_master(struct ubifs_info *c)
+{
+	struct ubifs_scan_leb *sleb;
+	struct ubifs_scan_node *snod;
+	int lnum, offs = 0, nodes_cnt, err;
+
+	lnum = UBIFS_MST_LNUM;
+
+	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
+	if (IS_ERR(sleb))
+		return PTR_ERR(sleb);
+	nodes_cnt = sleb->nodes_cnt;
+	if (nodes_cnt > 0) {
+		snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
+				  list);
+		if (snod->type != UBIFS_MST_NODE)
+			goto out_dump;
+		memcpy(c->mst_node, snod->node, snod->len);
+		offs = snod->offs;
+	}
+	ubifs_scan_destroy(sleb);
+
+	lnum += 1;
+
+	sleb = ubifs_scan(c, lnum, 0, c->sbuf, 1);
+	if (IS_ERR(sleb))
+		return PTR_ERR(sleb);
+	if (sleb->nodes_cnt != nodes_cnt)
+		goto out;
+	if (!sleb->nodes_cnt)
+		goto out;
+	snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
+	if (snod->type != UBIFS_MST_NODE)
+		goto out_dump;
+	if (snod->offs != offs)
+		goto out;
+	if (ubifs_compare_master_node(c, c->mst_node, snod->node))
+		goto out;
+
+	c->mst_offs = offs;
+	ubifs_scan_destroy(sleb);
+
+	if (!ubifs_authenticated(c))
+		return 0;
+
+	if (ubifs_hmac_zero(c, c->mst_node->hmac)) {
+		err = mst_node_check_hash(c, c->mst_node,
+					  c->sup_node->hash_mst);
+		if (err)
+			ubifs_err(c, "Failed to verify master node hash");
+	} else {
+		err = ubifs_node_verify_hmac(c, c->mst_node,
+					sizeof(struct ubifs_mst_node),
+					offsetof(struct ubifs_mst_node, hmac));
+		if (err)
+			ubifs_err(c, "Failed to verify master node HMAC");
+	}
+
+	if (err)
+		return -EPERM;
+
+	return 0;
+
+out:
+	ubifs_scan_destroy(sleb);
+	return -EUCLEAN;
+
+out_dump:
+	ubifs_err(c, "unexpected node type %d master LEB %d:%d",
+		  snod->type, lnum, snod->offs);
+	ubifs_scan_destroy(sleb);
+	return -EINVAL;
+}
+
+/**
+ * validate_master - validate master node.
+ * @c: UBIFS file-system description object
+ *
+ * This function validates data which was read from master node. Returns zero
+ * if the data is all right and %-EINVAL if not.
+ */
+static int validate_master(const struct ubifs_info *c)
+{
+	long long main_sz;
+	int err;
+
+	if (c->max_sqnum >= SQNUM_WATERMARK) {
+		err = 1;
+		goto out;
+	}
+
+	if (c->cmt_no >= c->max_sqnum) {
+		err = 2;
+		goto out;
+	}
+
+	if (c->highest_inum >= INUM_WATERMARK) {
+		err = 3;
+		goto out;
+	}
+
+	if (c->lhead_lnum < UBIFS_LOG_LNUM ||
+	    c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs ||
+	    c->lhead_offs < 0 || c->lhead_offs >= c->leb_size ||
+	    c->lhead_offs & (c->min_io_size - 1)) {
+		err = 4;
+		goto out;
+	}
+
+	if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first ||
+	    c->zroot.offs >= c->leb_size || c->zroot.offs & 7) {
+		err = 5;
+		goto out;
+	}
+
+	if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len ||
+	    c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) {
+		err = 6;
+		goto out;
+	}
+
+	if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) {
+		err = 7;
+		goto out;
+	}
+
+	if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first ||
+	    c->ihead_offs % c->min_io_size || c->ihead_offs < 0 ||
+	    c->ihead_offs > c->leb_size || c->ihead_offs & 7) {
+		err = 8;
+		goto out;
+	}
+
+	main_sz = (long long)c->main_lebs * c->leb_size;
+	if (c->bi.old_idx_sz & 7 || c->bi.old_idx_sz >= main_sz) {
+		err = 9;
+		goto out;
+	}
+
+	if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last ||
+	    c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) {
+		err = 10;
+		goto out;
+	}
+
+	if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last ||
+	    c->nhead_offs < 0 || c->nhead_offs % c->min_io_size ||
+	    c->nhead_offs > c->leb_size) {
+		err = 11;
+		goto out;
+	}
+
+	if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last ||
+	    c->ltab_offs < 0 ||
+	    c->ltab_offs + c->ltab_sz > c->leb_size) {
+		err = 12;
+		goto out;
+	}
+
+	if (c->big_lpt && (c->lsave_lnum < c->lpt_first ||
+	    c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 ||
+	    c->lsave_offs + c->lsave_sz > c->leb_size)) {
+		err = 13;
+		goto out;
+	}
+
+	if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) {
+		err = 14;
+		goto out;
+	}
+
+	if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) {
+		err = 15;
+		goto out;
+	}
+
+	if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) {
+		err = 16;
+		goto out;
+	}
+
+	if (c->lst.total_free < 0 || c->lst.total_free > main_sz ||
+	    c->lst.total_free & 7) {
+		err = 17;
+		goto out;
+	}
+
+	if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) {
+		err = 18;
+		goto out;
+	}
+
+	if (c->lst.total_used < 0 || (c->lst.total_used & 7)) {
+		err = 19;
+		goto out;
+	}
+
+	if (c->lst.total_free + c->lst.total_dirty +
+	    c->lst.total_used > main_sz) {
+		err = 20;
+		goto out;
+	}
+
+	if (c->lst.total_dead + c->lst.total_dark +
+	    c->lst.total_used + c->bi.old_idx_sz > main_sz) {
+		err = 21;
+		goto out;
+	}
+
+	if (c->lst.total_dead < 0 ||
+	    c->lst.total_dead > c->lst.total_free + c->lst.total_dirty ||
+	    c->lst.total_dead & 7) {
+		err = 22;
+		goto out;
+	}
+
+	if (c->lst.total_dark < 0 ||
+	    c->lst.total_dark > c->lst.total_free + c->lst.total_dirty ||
+	    c->lst.total_dark & 7) {
+		err = 23;
+		goto out;
+	}
+
+	return 0;
+
+out:
+	ubifs_err(c, "bad master node at offset %d error %d", c->mst_offs, err);
+	ubifs_dump_node(c, c->mst_node, c->mst_node_alsz);
+	return -EINVAL;
+}
+
+/**
+ * ubifs_read_master - read master node.
+ * @c: UBIFS file-system description object
+ *
+ * This function finds and reads the master node during file-system mount. If
+ * the flash is empty, it creates default master node as well. Returns zero in
+ * case of success and a negative error code in case of failure.
+ */
+int ubifs_read_master(struct ubifs_info *c)
+{
+	int err, old_leb_cnt;
+
+	c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL);
+	if (!c->mst_node)
+		return -ENOMEM;
+
+	err = scan_for_master(c);
+	if (err) {
+		if (err == -EUCLEAN)
+			err = ubifs_recover_master_node(c);
+		if (err)
+			/*
+			 * Note, we do not free 'c->mst_node' here because the
+			 * unmount routine will take care of this.
+			 */
+			return err;
+	}
+
+	/* Make sure that the recovery flag is clear */
+	c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY);
+
+	c->max_sqnum       = le64_to_cpu(c->mst_node->ch.sqnum);
+	c->highest_inum    = le64_to_cpu(c->mst_node->highest_inum);
+	c->cmt_no          = le64_to_cpu(c->mst_node->cmt_no);
+	c->zroot.lnum      = le32_to_cpu(c->mst_node->root_lnum);
+	c->zroot.offs      = le32_to_cpu(c->mst_node->root_offs);
+	c->zroot.len       = le32_to_cpu(c->mst_node->root_len);
+	c->lhead_lnum      = le32_to_cpu(c->mst_node->log_lnum);
+	c->gc_lnum         = le32_to_cpu(c->mst_node->gc_lnum);
+	c->ihead_lnum      = le32_to_cpu(c->mst_node->ihead_lnum);
+	c->ihead_offs      = le32_to_cpu(c->mst_node->ihead_offs);
+	c->bi.old_idx_sz   = le64_to_cpu(c->mst_node->index_size);
+	c->lpt_lnum        = le32_to_cpu(c->mst_node->lpt_lnum);
+	c->lpt_offs        = le32_to_cpu(c->mst_node->lpt_offs);
+	c->nhead_lnum      = le32_to_cpu(c->mst_node->nhead_lnum);
+	c->nhead_offs      = le32_to_cpu(c->mst_node->nhead_offs);
+	c->ltab_lnum       = le32_to_cpu(c->mst_node->ltab_lnum);
+	c->ltab_offs       = le32_to_cpu(c->mst_node->ltab_offs);
+	c->lsave_lnum      = le32_to_cpu(c->mst_node->lsave_lnum);
+	c->lsave_offs      = le32_to_cpu(c->mst_node->lsave_offs);
+	c->lscan_lnum      = le32_to_cpu(c->mst_node->lscan_lnum);
+	c->lst.empty_lebs  = le32_to_cpu(c->mst_node->empty_lebs);
+	c->lst.idx_lebs    = le32_to_cpu(c->mst_node->idx_lebs);
+	old_leb_cnt        = le32_to_cpu(c->mst_node->leb_cnt);
+	c->lst.total_free  = le64_to_cpu(c->mst_node->total_free);
+	c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty);
+	c->lst.total_used  = le64_to_cpu(c->mst_node->total_used);
+	c->lst.total_dead  = le64_to_cpu(c->mst_node->total_dead);
+	c->lst.total_dark  = le64_to_cpu(c->mst_node->total_dark);
+
+	ubifs_copy_hash(c, c->mst_node->hash_root_idx, c->zroot.hash);
+
+	c->calc_idx_sz = c->bi.old_idx_sz;
+
+	if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
+		c->no_orphs = 1;
+
+	if (old_leb_cnt != c->leb_cnt) {
+		/* The file system has been resized */
+		int growth = c->leb_cnt - old_leb_cnt;
+
+		if (c->leb_cnt < old_leb_cnt ||
+		    c->leb_cnt < UBIFS_MIN_LEB_CNT) {
+			ubifs_err(c, "bad leb_cnt on master node");
+			ubifs_dump_node(c, c->mst_node, c->mst_node_alsz);
+			return -EINVAL;
+		}
+
+		dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs",
+			old_leb_cnt, c->leb_cnt);
+		c->lst.empty_lebs += growth;
+		c->lst.total_free += growth * (long long)c->leb_size;
+		c->lst.total_dark += growth * (long long)c->dark_wm;
+
+		/*
+		 * Reflect changes back onto the master node. N.B. the master
+		 * node gets written immediately whenever mounting (or
+		 * remounting) in read-write mode, so we do not need to write it
+		 * here.
+		 */
+		c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt);
+		c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs);
+		c->mst_node->total_free = cpu_to_le64(c->lst.total_free);
+		c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark);
+	}
+
+	err = validate_master(c);
+	if (err)
+		return err;
+
+	err = dbg_old_index_check_init(c, &c->zroot);
+
+	return err;
+}
+
+/**
+ * ubifs_write_master - write master node.
+ * @c: UBIFS file-system description object
+ *
+ * This function writes the master node. Returns zero in case of success and a
+ * negative error code in case of failure. The master node is written twice to
+ * enable recovery.
+ */
+int ubifs_write_master(struct ubifs_info *c)
+{
+	int err, lnum, offs, len;
+
+	ubifs_assert(c, !c->ro_media && !c->ro_mount);
+	if (c->ro_error)
+		return -EROFS;
+
+	lnum = UBIFS_MST_LNUM;
+	offs = c->mst_offs + c->mst_node_alsz;
+	len = UBIFS_MST_NODE_SZ;
+
+	if (offs + UBIFS_MST_NODE_SZ > c->leb_size) {
+		err = ubifs_leb_unmap(c, lnum);
+		if (err)
+			return err;
+		offs = 0;
+	}
+
+	c->mst_offs = offs;
+	c->mst_node->highest_inum = cpu_to_le64(c->highest_inum);
+
+	ubifs_copy_hash(c, c->zroot.hash, c->mst_node->hash_root_idx);
+	err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs,
+				    offsetof(struct ubifs_mst_node, hmac));
+	if (err)
+		return err;
+
+	lnum += 1;
+
+	if (offs == 0) {
+		err = ubifs_leb_unmap(c, lnum);
+		if (err)
+			return err;
+	}
+	err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs,
+				    offsetof(struct ubifs_mst_node, hmac));
+
+	return err;
+}