[PATCH ndctl 3/4] cxl/region: fix an out of bounds access in to_csv()

[Vishal Verma]

Static analysis reports that when 'csv' is allocated for 'len' bytes,
writing to csv[len] results in an out of bounds access. Fix this
truncation operation to instead write the NUL terminator to csv[len -
1], which is the last byte of the memory allocated.

Fixes: 3d6cd829ec08 ("cxl/region: Use cxl_filter_walk() to gather create-region 
targets")
Cc: Dan Williams <dan.j.willi...@intel.com>
Signed-off-by: Vishal Verma <vishal.l.ve...@intel.com>
---
 cxl/region.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cxl/region.c b/cxl/region.c
index 9a81113..89be9b5 100644
--- a/cxl/region.c
+++ b/cxl/region.c
@@ -156,7 +156,7 @@ static const char *to_csv(int *count, const char **strings)
                        cursor += snprintf(csv + cursor, len - cursor, "%s%s",
                                           arg, i + 1 < new_count ? "," : "");
                        if (cursor >= len) {
-                               csv[len] = 0;
+                               csv[len - 1] = 0;
                                break;
                        }
                }

-- 
2.39.0