[Ocfs2-devel] [PATCH] ocfs2/dlm: don't access beyond bitmap size

[Sunil Mushran]

Signed-off-by: Sunil Mushran<sunil.mushran at oracle.com>


On 06/30/2010 05:23 AM, Wengang Wang wrote:
> dlm->recovery_map is defined as
> 	unsigned long recovery_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
>
> We should treat O2NM_MAX_NODES as the bit map size in bits.
> This patches fixes a bit operation that takes O2NM_MAX_NODES + 1 as bitmap size.
>
> Signed-off-by: Wengang Wang<wen.gang.wang at oracle.com>
> ---
>   fs/ocfs2/dlm/dlmrecovery.c |    2 +-
>   1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
> index f8b75ce..9dfaac7 100644
> --- a/fs/ocfs2/dlm/dlmrecovery.c
> +++ b/fs/ocfs2/dlm/dlmrecovery.c
> @@ -463,7 +463,7 @@ static int dlm_do_recovery(struct dlm_ctxt *dlm)
>   	if (dlm->reco.dead_node == O2NM_INVALID_NODE_NUM) {
>   		int bit;
>
> -		bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES+1, 0);
> +		bit = find_next_bit (dlm->recovery_map, O2NM_MAX_NODES, 0);
>   		if (bit>= O2NM_MAX_NODES || bit<  0)
>   			dlm_set_reco_dead_node(dlm, O2NM_INVALID_NODE_NUM);
>   		else
>