[QUEUED v0 06/19] stm class: Fix an off-by-one in master array allocation

[Alexander Shishkin]

From: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>

Since both sw_start and sw_end are master indices, the size of array
that holds them is sw_end - sw_start + 1, which the current code gets
wrong, allocating one item less than required.

This patch corrects the allocation size, avoiding potential slab
corruption.

Signed-off-by: Chunyan Zhang <zhang.chunyan@xxxxxxxxxx>
[alexander.shishkin@xxxxxxxxxxxxxxx: re-wrote the commit message]
Signed-off-by: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx>
---
 drivers/hwtracing/stm/core.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c
index ddcb606ace..40a8b79ab7 100644
--- a/drivers/hwtracing/stm/core.c
+++ b/drivers/hwtracing/stm/core.c
@@ -618,7 +618,7 @@ int stm_register_device(struct device *parent, struct stm_data *stm_data,
 	if (!stm_data->packet || !stm_data->sw_nchannels)
 		return -EINVAL;
 
-	nmasters = stm_data->sw_end - stm_data->sw_start;
+	nmasters = stm_data->sw_end - stm_data->sw_start + 1;
 	stm = kzalloc(sizeof(*stm) + nmasters * sizeof(void *), GFP_KERNEL);
 	if (!stm)
 		return -ENOMEM;
-- 
2.7.0