diff options
Diffstat (limited to 'fs/ubifs')
| -rw-r--r-- | fs/ubifs/master.c | 61 | ||||
| -rw-r--r-- | fs/ubifs/recovery.c | 9 | ||||
| -rw-r--r-- | fs/ubifs/ubifs.h | 1 |
3 files changed, 61 insertions, 10 deletions
diff --git a/fs/ubifs/master.c b/fs/ubifs/master.c index 0ca9d3513b4d..5ea51bbd14c7 100644 --- a/fs/ubifs/master.c +++ b/fs/ubifs/master.c @@ -25,6 +25,42 @@ #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; } diff --git a/fs/ubifs/recovery.c b/fs/ubifs/recovery.c index 984e30e83c0b..5c1334e6bc81 100644 --- a/fs/ubifs/recovery.c +++ b/fs/ubifs/recovery.c @@ -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) { diff --git a/fs/ubifs/ubifs.h b/fs/ubifs/ubifs.h index 7e519a4885a8..c26d3c600e4d 100644 --- a/fs/ubifs/ubifs.h +++ b/fs/ubifs/ubifs.h @@ -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); |