If there are no multipath devices, show_maps_json sets the maximum size
of the reply buffer to 0. Having a size of 0 causes the calls to calloc
and realloc to behave in ways that the code isn't designed to handle,
leading to a double-free crash. Instead, show_maps_json should just
use the INITIAL_REPLY_LEN if there are no multipath devices.
Signed-off-by: Benjamin Marzinski <bmarzins@xxxxxxxxxx>
---
multipathd/cli_handlers.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/multipathd/cli_handlers.c b/multipathd/cli_handlers.c
index 04c7386..7b0d00c 100644
--- a/multipathd/cli_handlers.c
+++ b/multipathd/cli_handlers.c
@@ -162,10 +162,12 @@ show_maps_json (char ** r, int * len, struct vectors * vecs)
struct multipath * mpp;
char * c;
char * reply;
- unsigned int maxlen = INITIAL_REPLY_LEN *
- PRINT_JSON_MULTIPLIER * VECTOR_SIZE(vecs->mpvec);
+ unsigned int maxlen = INITIAL_REPLY_LEN;
int again = 1;
+ if (VECTOR_SIZE(vecs->mpvec) > 0)
+ maxlen *= PRINT_JSON_MULTIPLIER * VECTOR_SIZE(vecs->mpvec);
+
vector_foreach_slot(vecs->mpvec, mpp, i) {
if (update_multipath(vecs, mpp->alias, 0)) {
return 1;
--
2.7.4
--
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