From: Jan Kara <jack@suse.cz>
To: Rustam Kovhaev <rkovhaev@gmail.com>
Cc: alex.shi@linux.alibaba.com, jack@suse.cz,
akpm@linux-foundation.org, yeyunfeng@huawei.com,
reiserfs-devel@vger.kernel.org, linux-kernel@vger.kernel.org,
gregkh@linuxfoundation.org
Subject: Re: [PATCH] reiserfs: add check for an invalid ih_entry_count
Date: Thu, 26 Nov 2020 16:57:54 +0100 [thread overview]
Message-ID: <20201126155754.GK422@quack2.suse.cz> (raw)
In-Reply-To: <20201101140958.3650143-1-rkovhaev@gmail.com>
On Sun 01-11-20 06:09:58, Rustam Kovhaev wrote:
> when directory item has an invalid value set for ih_entry_count it might
> trigger use-after-free or out-of-bounds read in bin_search_in_dir_item()
>
> ih_entry_count * IH_SIZE for directory item should not be larger than
> ih_item_len
>
> Reported-and-tested-by: syzbot+83b6f7cf9922cae5c4d7@syzkaller.appspotmail.com
> Link: https://syzkaller.appspot.com/bug?extid=83b6f7cf9922cae5c4d7
> Signed-off-by: Rustam Kovhaev <rkovhaev@gmail.com>
Thanks! I've added the patch to my tree and will push it to Linus.
Honza
> ---
> fs/reiserfs/stree.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
> diff --git a/fs/reiserfs/stree.c b/fs/reiserfs/stree.c
> index 8bf88d690729..476a7ff49482 100644
> --- a/fs/reiserfs/stree.c
> +++ b/fs/reiserfs/stree.c
> @@ -454,6 +454,12 @@ static int is_leaf(char *buf, int blocksize, struct buffer_head *bh)
> "(second one): %h", ih);
> return 0;
> }
> + if (is_direntry_le_ih(ih) && (ih_item_len(ih) < (ih_entry_count(ih) * IH_SIZE))) {
> + reiserfs_warning(NULL, "reiserfs-5093",
> + "item entry count seems wrong %h",
> + ih);
> + return 0;
> + }
> prev_location = ih_location(ih);
> }
>
> --
> 2.28.0
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
prev parent reply other threads:[~2020-11-26 15:57 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-11-01 14:09 [PATCH] reiserfs: add check for an invalid ih_entry_count Rustam Kovhaev
2020-11-26 15:57 ` Jan Kara [this message]
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