[Ocfs2-tools-devel] [PATCH] mkfs.ocfs2: return failed when heartbeat file corruption

[Jia Guo]

It will cause kernel panic if we set the heartbeat slot number
less than O2NM_MAX_NODES. The panic stack is generated as follows:

o2hb_thread
    \-o2hb_do_disk_heartbeat
        |-membership_change |= o2hb_check_slot(reg, &reg->hr_slots[i]);

The value of i will out of array range(reg->hr_slots) when there is
a node number greater than the heartbeat slot number we set.

We need check the value of heartbeat slot number.

Signed-off-by: Jia Guo <guojia12 at huawei.com>
---
 libocfs2/heartbeat.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/libocfs2/heartbeat.c b/libocfs2/heartbeat.c
index b83cdfb..aa5afa5 100644
--- a/libocfs2/heartbeat.c
+++ b/libocfs2/heartbeat.c
@@ -98,7 +98,10 @@ errcode_t ocfs2_fill_heartbeat_desc(ocfs2_filesys *fs,
 	blocks = ocfs2_rec_clusters(0, rec) << cluster_bits;
 	blocks >>= block_bits;

-	if (blocks > O2NM_MAX_NODES)
+	if (blocks < O2NM_MAX_NODES) {
+		ret = OCFS2_ET_BAD_HEARTBEAT_FILE;
+		goto leave;
+	} else
 		blocks = O2NM_MAX_NODES;

 	start_block = rec->e_blkno << block_bits;