Gitweb:     
http://git.kernel.org/git/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=cf0594625083111ae522496dc1c256f7476939c2
Commit:     cf0594625083111ae522496dc1c256f7476939c2
Parent:     467bc461d2845f6a04b124bca1ae6ecc554e1ee5
Author:     Eric Sandeen <[EMAIL PROTECTED]>
AuthorDate: Tue Jan 8 15:33:20 2008 -0800
Committer:  Linus Torvalds <[EMAIL PROTECTED]>
CommitDate: Tue Jan 8 16:10:36 2008 -0800

    hfs: handle more on-disk corruptions without oopsing
    
    hfs seems prone to bad things when it encounters on disk corruption.  Many
    values are read from disk, and used as lengths to memcpy, as an example.
    This patch fixes up several of these problematic cases.
    
    o sanity check the on-disk maximum key lengths on mount
      (these are set to a defined value at mkfs time and shouldn't differ)
    o check on-disk node keylens against the maximum key length for each tree
    o fix hfs_btree_open so that going out via free_tree: doesn't wind
      up in hfs_releasepage, which wants to follow the very pointer
      we were trying to set up:
        HFS_SB(sb)->cat_tree = hfs_btree_open()
                ...
                failure gets to hfs_releasepage and tries
                to follow HFS_SB(sb)->cat_tree
    
    Tested with the fsfuzzer; it survives more than it used to.
    
    Signed-off-by: Eric Sandeen <[EMAIL PROTECTED]>
    Cc: Roman Zippel <[EMAIL PROTECTED]>
    Signed-off-by: Andrew Morton <[EMAIL PROTECTED]>
    Signed-off-by: Linus Torvalds <[EMAIL PROTECTED]>
---
 fs/hfs/bfind.c |   12 ++++++++++++
 fs/hfs/brec.c  |   15 +++++++++++++--
 fs/hfs/btree.c |   13 ++++++++++++-
 fs/hfs/hfs.h   |    5 +++++
 4 files changed, 42 insertions(+), 3 deletions(-)

diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c
index f13f149..f8452a0 100644
--- a/fs/hfs/bfind.c
+++ b/fs/hfs/bfind.c
@@ -52,6 +52,10 @@ int __hfs_brec_find(struct hfs_bnode *bnode, struct 
hfs_find_data *fd)
                rec = (e + b) / 2;
                len = hfs_brec_lenoff(bnode, rec, &off);
                keylen = hfs_brec_keylen(bnode, rec);
+               if (keylen == HFS_BAD_KEYLEN) {
+                       res = -EINVAL;
+                       goto done;
+               }
                hfs_bnode_read(bnode, fd->key, off, keylen);
                cmpval = bnode->tree->keycmp(fd->key, fd->search_key);
                if (!cmpval) {
@@ -67,6 +71,10 @@ int __hfs_brec_find(struct hfs_bnode *bnode, struct 
hfs_find_data *fd)
        if (rec != e && e >= 0) {
                len = hfs_brec_lenoff(bnode, e, &off);
                keylen = hfs_brec_keylen(bnode, e);
+               if (keylen == HFS_BAD_KEYLEN) {
+                       res = -EINVAL;
+                       goto done;
+               }
                hfs_bnode_read(bnode, fd->key, off, keylen);
        }
 done:
@@ -198,6 +206,10 @@ int hfs_brec_goto(struct hfs_find_data *fd, int cnt)
 
        len = hfs_brec_lenoff(bnode, fd->record, &off);
        keylen = hfs_brec_keylen(bnode, fd->record);
+       if (keylen == HFS_BAD_KEYLEN) {
+               res = -EINVAL;
+               goto out;
+       }
        fd->keyoffset = off;
        fd->keylength = keylen;
        fd->entryoffset = off + keylen;
diff --git a/fs/hfs/brec.c b/fs/hfs/brec.c
index 5c87cf4..8626ee3 100644
--- a/fs/hfs/brec.c
+++ b/fs/hfs/brec.c
@@ -44,10 +44,21 @@ u16 hfs_brec_keylen(struct hfs_bnode *node, u16 rec)
                recoff = hfs_bnode_read_u16(node, node->tree->node_size - (rec 
+ 1) * 2);
                if (!recoff)
                        return 0;
-               if (node->tree->attributes & HFS_TREE_BIGKEYS)
+               if (node->tree->attributes & HFS_TREE_BIGKEYS) {
                        retval = hfs_bnode_read_u16(node, recoff) + 2;
-               else
+                       if (retval > node->tree->max_key_len + 2) {
+                               printk(KERN_ERR "hfs: keylen %d too large\n",
+                                       retval);
+                               retval = HFS_BAD_KEYLEN;
+                       }
+               } else {
                        retval = (hfs_bnode_read_u8(node, recoff) | 1) + 1;
+                       if (retval > node->tree->max_key_len + 1) {
+                               printk(KERN_ERR "hfs: keylen %d too large\n",
+                                       retval);
+                               retval = HFS_BAD_KEYLEN;
+                       }
+               }
        }
        return retval;
 }
diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c
index 8a3a650..31284c7 100644
--- a/fs/hfs/btree.c
+++ b/fs/hfs/btree.c
@@ -81,6 +81,17 @@ struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 
id, btree_keycmp ke
                goto fail_page;
        if (!tree->node_count)
                goto fail_page;
+       if ((id == HFS_EXT_CNID) && (tree->max_key_len != HFS_MAX_EXT_KEYLEN)) {
+               printk(KERN_ERR "hfs: invalid extent max_key_len %d\n",
+                       tree->max_key_len);
+               goto fail_page;
+       }
+       if ((id == HFS_CAT_CNID) && (tree->max_key_len != HFS_MAX_CAT_KEYLEN)) {
+               printk(KERN_ERR "hfs: invalid catalog max_key_len %d\n",
+                       tree->max_key_len);
+               goto fail_page;
+       }
+
        tree->node_size_shift = ffs(size) - 1;
        tree->pages_per_bnode = (tree->node_size + PAGE_CACHE_SIZE - 1) >> 
PAGE_CACHE_SHIFT;
 
@@ -89,9 +100,9 @@ struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 
id, btree_keycmp ke
        return tree;
 
  fail_page:
-       tree->inode->i_mapping->a_ops = &hfs_aops;
        page_cache_release(page);
  free_tree:
+       tree->inode->i_mapping->a_ops = &hfs_aops;
        iput(tree->inode);
        kfree(tree);
        return NULL;
diff --git a/fs/hfs/hfs.h b/fs/hfs/hfs.h
index 1445e3a..c6aae61 100644
--- a/fs/hfs/hfs.h
+++ b/fs/hfs/hfs.h
@@ -28,6 +28,8 @@
 #define HFS_MAX_NAMELEN                128
 #define HFS_MAX_VALENCE                32767U
 
+#define HFS_BAD_KEYLEN         0xFF
+
 /* Meanings of the drAtrb field of the MDB,
  * Reference: _Inside Macintosh: Files_ p. 2-61
  */
@@ -167,6 +169,9 @@ typedef union hfs_btree_key {
        struct hfs_ext_key ext;
 } hfs_btree_key;
 
+#define HFS_MAX_CAT_KEYLEN     (sizeof(struct hfs_cat_key) - sizeof(u8))
+#define HFS_MAX_EXT_KEYLEN     (sizeof(struct hfs_ext_key) - sizeof(u8))
+
 typedef union hfs_btree_key btree_key;
 
 struct hfs_extent {
-
To unsubscribe from this list: send the line "unsubscribe git-commits-head" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Reply via email to