Ocfs2 devel - Jun 2010 - [PATCH] ocfs2/dlm: don't access beyond bitmap size

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
-- 
1.6.6.1

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
>

On Wed, Jun 30, 2010 at 08:23:30PM +0800, 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>
This patch is now in the 'fixes' branch of ocfs2.git.

Joel

-- 

 The zen have a saying:
 "When you learn how to listen, ANYONE can be your teacher."

Joel Becker
Consulting Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127