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-rw-r--r--fs/ubifs/lpt.c184
1 files changed, 174 insertions, 10 deletions
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c
index 31393370e334..d1d5e96350dd 100644
--- a/fs/ubifs/lpt.c
+++ b/fs/ubifs/lpt.c
@@ -604,11 +604,12 @@ static int calc_pnode_num_from_parent(const struct ubifs_info *c,
* @lpt_first: LEB number of first LPT LEB
* @lpt_lebs: number of LEBs for LPT is passed and returned here
* @big_lpt: use big LPT model is passed and returned here
+ * @hash: hash of the LPT is returned here
*
* This function returns %0 on success and a negative error code on failure.
*/
int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
- int *lpt_lebs, int *big_lpt)
+ int *lpt_lebs, int *big_lpt, u8 *hash)
{
int lnum, err = 0, node_sz, iopos, i, j, cnt, len, alen, row;
int blnum, boffs, bsz, bcnt;
@@ -617,6 +618,7 @@ int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
void *buf = NULL, *p;
struct ubifs_lpt_lprops *ltab = NULL;
int *lsave = NULL;
+ struct shash_desc *desc;
err = calc_dflt_lpt_geom(c, main_lebs, big_lpt);
if (err)
@@ -630,6 +632,10 @@ int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
/* Needed by 'ubifs_pack_lsave()' */
c->main_first = c->leb_cnt - *main_lebs;
+ desc = ubifs_hash_get_desc(c);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
lsave = kmalloc_array(c->lsave_cnt, sizeof(int), GFP_KERNEL);
pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_KERNEL);
nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_KERNEL);
@@ -677,6 +683,10 @@ int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
/* Add first pnode */
ubifs_pack_pnode(c, p, pnode);
+ err = ubifs_shash_update(c, desc, p, c->pnode_sz);
+ if (err)
+ goto out;
+
p += c->pnode_sz;
len = c->pnode_sz;
pnode->num += 1;
@@ -711,6 +721,10 @@ int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
len = 0;
}
ubifs_pack_pnode(c, p, pnode);
+ err = ubifs_shash_update(c, desc, p, c->pnode_sz);
+ if (err)
+ goto out;
+
p += c->pnode_sz;
len += c->pnode_sz;
/*
@@ -830,6 +844,10 @@ int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
if (err)
goto out;
+ err = ubifs_shash_final(c, desc, hash);
+ if (err)
+ goto out;
+
c->nhead_lnum = lnum;
c->nhead_offs = ALIGN(len, c->min_io_size);
@@ -853,6 +871,7 @@ int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
out:
c->ltab = NULL;
+ kfree(desc);
kfree(lsave);
vfree(ltab);
vfree(buf);
@@ -1439,26 +1458,25 @@ struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
}
/**
- * ubifs_lpt_lookup - lookup LEB properties in the LPT.
+ * ubifs_pnode_lookup - lookup a pnode in the LPT.
* @c: UBIFS file-system description object
- * @lnum: LEB number to lookup
+ * @i: pnode number (0 to (main_lebs - 1) / UBIFS_LPT_FANOUT)
*
- * This function returns a pointer to the LEB properties on success or a
- * negative error code on failure.
+ * This function returns a pointer to the pnode on success or a negative
+ * error code on failure.
*/
-struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
+struct ubifs_pnode *ubifs_pnode_lookup(struct ubifs_info *c, int i)
{
- int err, i, h, iip, shft;
+ int err, h, iip, shft;
struct ubifs_nnode *nnode;
- struct ubifs_pnode *pnode;
if (!c->nroot) {
err = ubifs_read_nnode(c, NULL, 0);
if (err)
return ERR_PTR(err);
}
+ i <<= UBIFS_LPT_FANOUT_SHIFT;
nnode = c->nroot;
- i = lnum - c->main_first;
shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
for (h = 1; h < c->lpt_hght; h++) {
iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
@@ -1468,7 +1486,24 @@ struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
return ERR_CAST(nnode);
}
iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
- pnode = ubifs_get_pnode(c, nnode, iip);
+ return ubifs_get_pnode(c, nnode, iip);
+}
+
+/**
+ * ubifs_lpt_lookup - lookup LEB properties in the LPT.
+ * @c: UBIFS file-system description object
+ * @lnum: LEB number to lookup
+ *
+ * This function returns a pointer to the LEB properties on success or a
+ * negative error code on failure.
+ */
+struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
+{
+ int i, iip;
+ struct ubifs_pnode *pnode;
+
+ i = lnum - c->main_first;
+ pnode = ubifs_pnode_lookup(c, i >> UBIFS_LPT_FANOUT_SHIFT);
if (IS_ERR(pnode))
return ERR_CAST(pnode);
iip = (i & (UBIFS_LPT_FANOUT - 1));
@@ -1620,6 +1655,131 @@ struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum)
}
/**
+ * ubifs_lpt_calc_hash - Calculate hash of the LPT pnodes
+ * @c: UBIFS file-system description object
+ * @hash: the returned hash of the LPT pnodes
+ *
+ * This function iterates over the LPT pnodes and creates a hash over them.
+ * Returns 0 for success or a negative error code otherwise.
+ */
+int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash)
+{
+ struct ubifs_nnode *nnode, *nn;
+ struct ubifs_cnode *cnode;
+ struct shash_desc *desc;
+ int iip = 0, i;
+ int bufsiz = max_t(int, c->nnode_sz, c->pnode_sz);
+ void *buf;
+ int err;
+
+ if (!ubifs_authenticated(c))
+ return 0;
+
+ desc = ubifs_hash_get_desc(c);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ buf = kmalloc(bufsiz, GFP_NOFS);
+ if (!buf) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ if (!c->nroot) {
+ err = ubifs_read_nnode(c, NULL, 0);
+ if (err)
+ return err;
+ }
+
+ cnode = (struct ubifs_cnode *)c->nroot;
+
+ while (cnode) {
+ nnode = cnode->parent;
+ nn = (struct ubifs_nnode *)cnode;
+ if (cnode->level > 1) {
+ while (iip < UBIFS_LPT_FANOUT) {
+ if (nn->nbranch[iip].lnum == 0) {
+ /* Go right */
+ iip++;
+ continue;
+ }
+
+ nnode = ubifs_get_nnode(c, nn, iip);
+ if (IS_ERR(nnode)) {
+ err = PTR_ERR(nnode);
+ goto out;
+ }
+
+ /* Go down */
+ iip = 0;
+ cnode = (struct ubifs_cnode *)nnode;
+ break;
+ }
+ if (iip < UBIFS_LPT_FANOUT)
+ continue;
+ } else {
+ struct ubifs_pnode *pnode;
+
+ for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
+ if (nn->nbranch[i].lnum == 0)
+ continue;
+ pnode = ubifs_get_pnode(c, nn, i);
+ if (IS_ERR(pnode)) {
+ err = PTR_ERR(pnode);
+ goto out;
+ }
+
+ ubifs_pack_pnode(c, buf, pnode);
+ err = ubifs_shash_update(c, desc, buf,
+ c->pnode_sz);
+ if (err)
+ goto out;
+ }
+ }
+ /* Go up and to the right */
+ iip = cnode->iip + 1;
+ cnode = (struct ubifs_cnode *)nnode;
+ }
+
+ err = ubifs_shash_final(c, desc, hash);
+out:
+ kfree(desc);
+ kfree(buf);
+
+ return err;
+}
+
+/**
+ * lpt_check_hash - check the hash of the LPT.
+ * @c: UBIFS file-system description object
+ *
+ * This function calculates a hash over all pnodes in the LPT and compares it with
+ * the hash stored in the master node. Returns %0 on success and a negative error
+ * code on failure.
+ */
+static int lpt_check_hash(struct ubifs_info *c)
+{
+ int err;
+ u8 hash[UBIFS_HASH_ARR_SZ];
+
+ if (!ubifs_authenticated(c))
+ return 0;
+
+ err = ubifs_lpt_calc_hash(c, hash);
+ if (err)
+ return err;
+
+ if (ubifs_check_hash(c, c->mst_node->hash_lpt, hash)) {
+ err = -EPERM;
+ ubifs_err(c, "Failed to authenticate LPT");
+ } else {
+ err = 0;
+ }
+
+ return err;
+}
+
+/**
* lpt_init_rd - initialize the LPT for reading.
* @c: UBIFS file-system description object
*
@@ -1660,6 +1820,10 @@ static int lpt_init_rd(struct ubifs_info *c)
if (err)
return err;
+ err = lpt_check_hash(c);
+ if (err)
+ return err;
+
dbg_lp("space_bits %d", c->space_bits);
dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-03 17:53:03 +0100