diff options
| -rw-r--r-- | fs/ubifs/lpt.c | 129 | ||||
| -rw-r--r-- | fs/ubifs/lpt_commit.c | 4 | ||||
| -rw-r--r-- | fs/ubifs/ubifs.h | 1 |
3 files changed, 134 insertions, 0 deletions
diff --git a/fs/ubifs/lpt.c b/fs/ubifs/lpt.c index 5f57af224b8f9..ee18305a6152d 100644 --- a/fs/ubifs/lpt.c +++ b/fs/ubifs/lpt.c @@ -1636,6 +1636,131 @@ 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 * @@ -1676,6 +1801,10 @@ 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); diff --git a/fs/ubifs/lpt_commit.c b/fs/ubifs/lpt_commit.c index 62d6a87d4f5d0..1f88caffdf2ac 100644 --- a/fs/ubifs/lpt_commit.c +++ b/fs/ubifs/lpt_commit.c @@ -1247,6 +1247,10 @@ int ubifs_lpt_start_commit(struct ubifs_info *c) if (err) goto out; + err = ubifs_lpt_calc_hash(c, c->mst_node->hash_lpt); + if (err) + goto out; + /* Copy the LPT's own lprops for end commit to write */ memcpy(c->ltab_cmt, c->ltab, sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs); diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 600a25b93a809..7e519a4885a8c 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -1961,6 +1961,7 @@ struct ubifs_nnode *ubifs_first_nnode(struct ubifs_info *c, int *hght); /* Needed only in debugging code in lpt_commit.c */ int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf, struct ubifs_nnode *nnode); +int ubifs_lpt_calc_hash(struct ubifs_info *c, u8 *hash); /* lpt_commit.c */ int ubifs_lpt_start_commit(struct ubifs_info *c); |