From 9f0083d83892fc93f71b74ab1344e8bfa44f0259 Mon Sep 17 00:00:00 2001 From: Florian Forster Date: Sun, 14 Aug 2016 21:36:27 +0200 Subject: [PATCH] ceph plugin: Rewrite the BUFFER_ADD() macro. I'm hoping that this fixes a potential integer underrun that may occur when unconditionally subtracting strlen(dest) from sizeof(dest). Issue: #1835 --- src/ceph.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/src/ceph.c b/src/ceph.c index 55cd64c6..5b792391 100644 --- a/src/ceph.c +++ b/src/ceph.c @@ -262,8 +262,11 @@ static int ceph_cb_boolean(void *ctx, int bool_val) #define BUFFER_ADD(dest, src) do { \ size_t dest_size = sizeof (dest); \ - strncat ((dest), (src), dest_size - strlen (dest)); \ - (dest)[dest_size - 1] = '\0'; \ + size_t dest_len = strlen (dest); \ + if (dest_size > dest_len) { \ + sstrncpy ((dest) + dest_len, (src), dest_size - dest_len); \ + } \ + (dest)[dest_size - 1] = 0; \ } while (0) static int @@ -271,11 +274,10 @@ ceph_cb_number(void *ctx, const char *number_val, yajl_len_t number_len) { yajl_struct *state = (yajl_struct*) ctx; char buffer[number_len+1]; - char key[2 * DATA_MAX_NAME_LEN]; + char key[2 * DATA_MAX_NAME_LEN] = { 0 }; _Bool latency_type = 0; int status; - key[0] = '\0'; memcpy(buffer, number_val, number_len); buffer[sizeof(buffer) - 1] = '\0'; -- 2.11.0