diff options
| author | Phillip Lougher <plougher@redhat.com> | 2011-11-02 13:38:01 -0700 |
|---|---|---|
| committer | Willy Tarreau <w@1wt.eu> | 2012-02-11 15:38:07 +0100 |
| commit | 3db7e32f7521df6f9b64a9b04abb00dd11ca5735 (patch) | |
| tree | e56cd7f167a09ba06daa405ccb70e38f630ca640 | |
| parent | 52556d4b189c73376320ff502204db73c1ce4455 (diff) | |
hfs: fix hfs_find_init() sb->ext_tree NULL ptr oops
commit 434a964daa14b9db083ce20404a4a2add54d037a upstream.
Clement Lecigne reports a filesystem which causes a kernel oops in
hfs_find_init() trying to dereference sb->ext_tree which is NULL.
This proves to be because the filesystem has a corrupted MDB extent
record, where the extents file does not fit into the first three extents
in the file record (the first blocks).
In hfs_get_block() when looking up the blocks for the extent file
(HFS_EXT_CNID), it fails the first blocks special case, and falls
through to the extent code (which ultimately calls hfs_find_init())
which is in the process of being initialised.
Hfs avoids this scenario by always having the extents b-tree fitting
into the first blocks (the extents B-tree can't have overflow extents).
The fix is to check at mount time that the B-tree fits into first
blocks, i.e. fail if HFS_I(inode)->alloc_blocks >=
HFS_I(inode)->first_blocks
Note, the existing commit 47f365eb57573 ("hfs: fix oops on mount with
corrupted btree extent records") becomes subsumed into this as a special
case, but only for the extents B-tree (HFS_EXT_CNID), it is perfectly
acceptable for the catalog B-Tree file to grow beyond three extents,
with the remaining extent descriptors in the extents overfow.
[WT: patch edited - 47f365eb57573 was missing from 2.6.27.x]
This fixes CVE-2011-2203
Reported-by: Clement LECIGNE <clement.lecigne@netasq.com>
Signed-off-by: Phillip Lougher <plougher@redhat.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Moritz Mühlenhoff <jmm@inutil.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Willy Tarreau <w@1wt.eu>
| -rw-r--r-- | fs/hfs/btree.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/fs/hfs/btree.c b/fs/hfs/btree.c index 9b9d6395bad..0609e710e4f 100644 --- a/fs/hfs/btree.c +++ b/fs/hfs/btree.c @@ -45,11 +45,26 @@ struct hfs_btree *hfs_btree_open(struct super_block *sb, u32 id, btree_keycmp ke case HFS_EXT_CNID: hfs_inode_read_fork(tree->inode, mdb->drXTExtRec, mdb->drXTFlSize, mdb->drXTFlSize, be32_to_cpu(mdb->drXTClpSiz)); + if (HFS_I(tree->inode)->alloc_blocks > + HFS_I(tree->inode)->first_blocks) { + printk(KERN_ERR "hfs: invalid btree extent records\n"); + unlock_new_inode(tree->inode); + goto free_inode; + } + tree->inode->i_mapping->a_ops = &hfs_btree_aops; break; case HFS_CAT_CNID: hfs_inode_read_fork(tree->inode, mdb->drCTExtRec, mdb->drCTFlSize, mdb->drCTFlSize, be32_to_cpu(mdb->drCTClpSiz)); + + if (!HFS_I(tree->inode)->first_blocks) { + printk(KERN_ERR "hfs: invalid btree extent records " + "(0 size).\n"); + unlock_new_inode(tree->inode); + goto free_inode; + } + tree->inode->i_mapping->a_ops = &hfs_btree_aops; break; default: |