ubfis: authentication: Authenticate master node (625700cc) · Commits · 戴 / test

fs/ubifs/master.c

+55 −6

Original line number	Diff line number	Diff line
		@@ -24,6 +24,42 @@

		#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 aswell 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;
		}

		/**
		* scan_for_master - search the valid master node.
		* @c: UBIFS file-system description object
		@@ -37,7 +73,7 @@ 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;
		int lnum, offs = 0, nodes_cnt, err;

		lnum = UBIFS_MST_LNUM;

		@@ -69,12 +105,23 @@ static int scan_for_master(struct ubifs_info *c)
		goto out_dump;
		if (snod->offs != offs)
		goto out;
		if (memcmp((void *)c->mst_node + UBIFS_CH_SZ,
		(void *)snod->node + UBIFS_CH_SZ,
		UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
		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;

		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");
		return -EPERM;
		}

		return 0;

		out:
		@@ -381,7 +428,8 @@ int ubifs_write_master(struct ubifs_info *c)
		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(c, c->mst_node, len, lnum, offs);
		err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs,
		offsetof(struct ubifs_mst_node, hmac));
		if (err)
		return err;

		@@ -392,7 +440,8 @@ int ubifs_write_master(struct ubifs_info *c)
		if (err)
		return err;
		}
		err = ubifs_write_node(c, c->mst_node, len, lnum, offs);
		err = ubifs_write_node_hmac(c, c->mst_node, len, lnum, offs,
		offsetof(struct ubifs_mst_node, hmac));

		return err;
		}

fs/ubifs/recovery.c

+5 −4

Original line number	Diff line number	Diff line
		@@ -212,7 +212,10 @@ static int write_rcvrd_mst_node(struct ubifs_info *c,
		save_flags = mst->flags;
		mst->flags \|= cpu_to_le32(UBIFS_MST_RCVRY);

		ubifs_prepare_node(c, mst, UBIFS_MST_NODE_SZ, 1);
		err = ubifs_prepare_node_hmac(c, mst, UBIFS_MST_NODE_SZ,
		offsetof(struct ubifs_mst_node, hmac), 1);
		if (err)
		goto out;
		err = ubifs_leb_change(c, lnum, mst, sz);
		if (err)
		goto out;
		@@ -264,9 +267,7 @@ int ubifs_recover_master_node(struct ubifs_info *c)
		offs2 = (void *)mst2 - buf2;
		if (offs1 == offs2) {
		/* Same offset, so must be the same */
		if (memcmp((void *)mst1 + UBIFS_CH_SZ,
		(void *)mst2 + UBIFS_CH_SZ,
		UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
		if (ubifs_compare_master_node(c, mst1, mst2))
		goto out_err;
		mst = mst1;
		} else if (offs2 + sz == offs1) {

fs/ubifs/ubifs.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -1900,6 +1900,7 @@ int ubifs_gc_should_commit(struct ubifs_info *c);
		void ubifs_wait_for_commit(struct ubifs_info *c);

		/* master.c */
		int ubifs_compare_master_node(struct ubifs_info c, void m1, void *m2);
		int ubifs_read_master(struct ubifs_info *c);
		int ubifs_write_master(struct ubifs_info *c);

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