From: "Theodore Y. Ts'o" <tytso@mit.edu>
To: Andreas Dilger <adilger@whamcloud.com>
Cc: linux-ext4@vger.kernel.org
Subject: Re: [PATCH] e2fsck: avoid overflow with very large dirs
Date: Wed, 4 Mar 2020 18:39:11 -0500 [thread overview]
Message-ID: <20200304233911.GI74069@mit.edu> (raw)
In-Reply-To: <1581469641-85696-1-git-send-email-adilger@whamcloud.com>
On Tue, Feb 11, 2020 at 06:07:21PM -0700, Andreas Dilger wrote:
> In alloc_size_dir() it multiples signed ints when allocating the
> buffer for rehashing an htree-indexed directory. This will overflow
> when the directory size is above 4GB, which is possible with largedir
> directories having about 100M entries, assuming an average 3/4 leaf
> fullness and 24-byte filenames, or fewer with longer filenames.
> The same problem exisgs in get_next_block().
>
> Similarly, the out_dir struct used a signed int for the number of
> blocks in the directory, which may result in a negative size if the
> directory is over 2GB (about 50M entries or fewer).
>
> Use appropriate unsigned variables for block counts, and use larger
> types for calculating the byte count for memory offsets/sizes.
>
> Such large directories not been seen yet, but are not too far away.
> The ext2fs_get_array() function will properly calculate the needed
> memory allocation, and detect overflow on 32-bit systems.
> Add ext2fs_resize_array() to do the same for array resize.
>
> Signed-off-by: Andreas Dilger <adilger@whamcloud.com>
> Lustre-bug-id: https://jira.whamcloud.com/browse/LU-13197
Applied, thanks. I had to make a slight change to fix a "merge
conflict" with the patch.
- Ted
next prev parent reply other threads:[~2020-03-04 23:39 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-07 1:09 [PATCH 1/9] e2fsck: fix e2fsck_allocate_memory() overflow Andreas Dilger
2020-02-07 1:09 ` [PATCH 2/9] e2fsck: use proper types for variables Andreas Dilger
2020-02-29 23:27 ` Theodore Y. Ts'o
2020-02-07 1:09 ` [PATCH 3/9] e2fsck: avoid mallinfo() if over 2GB allocated Andreas Dilger
2020-02-29 23:28 ` Theodore Y. Ts'o
2020-02-07 1:09 ` [PATCH 4/9] e2fsck: reduce memory usage for many directories Andreas Dilger
2020-02-29 23:29 ` Theodore Y. Ts'o
2020-02-07 1:09 ` [PATCH 5/9] debugfs: allow comment lines in command file Andreas Dilger
2020-02-29 23:32 ` Theodore Y. Ts'o
2020-02-07 1:09 ` [PATCH 6/9] debugfs: print inode numbers as unsigned Andreas Dilger
2020-02-29 23:34 ` Theodore Y. Ts'o
2020-02-07 1:09 ` [PATCH 7/9] e2fsck: fix overflow if more than 4B inodes Andreas Dilger
2020-02-29 23:35 ` Theodore Y. Ts'o
2020-02-07 1:09 ` [PATCH 8/9] e2fsck: consistently use ext2fs_get_mem() Andreas Dilger
2020-02-29 23:36 ` Theodore Y. Ts'o
2020-03-04 23:23 ` Theodore Y. Ts'o
2020-02-07 1:09 ` [PATCH 9/9] misc: handle very large files with filefrag Andreas Dilger
2020-03-04 23:27 ` Theodore Y. Ts'o
2020-02-12 0:58 ` [PATCH] " Andreas Dilger
2020-02-12 1:09 ` Andreas Dilger
2020-02-12 1:07 ` [PATCH] e2fsck: avoid overflow with very large dirs Andreas Dilger
2020-03-04 23:39 ` Theodore Y. Ts'o [this message]
2020-02-29 23:25 ` [PATCH 1/9] e2fsck: fix e2fsck_allocate_memory() overflow Theodore Y. Ts'o
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