[gpsd-dev] [PATCH] Prevent client crashes if one calls gps_close() multiple times

[Robert Norris]

privdata must be explicitly set to NULL after use,
 otherwise if gps_close() is (incorrectly) called again before
 a new gps_open() then a double free condition can occur.
---
 libgps_shm.c  | 1 +
 libgps_sock.c | 1 +
 2 files changed, 2 insertions(+)

diff --git a/libgps_shm.c b/libgps_shm.c
index b256249..a0dfdde 100644
--- a/libgps_shm.c
+++ b/libgps_shm.c
@@ -60,6 +60,7 @@ int gps_shm_open(struct gps_data_t *gpsdata)
     if (PRIVATE(gpsdata)->shmseg == (void *) -1) {
        /* attach failed for sume unknown reason */
        free(gpsdata->privdata);
+       gpsdata->privdata = NULL;
        return -2;
     }
 #ifndef USE_QT
diff --git a/libgps_sock.c b/libgps_sock.c
index d056515..a7ac672 100644
--- a/libgps_sock.c
+++ b/libgps_sock.c
@@ -118,6 +118,7 @@ int gps_sock_close(struct gps_data_t *gpsdata)
     int status;
 
     free(PRIVATE(gpsdata));
+    gpsdata->privdata = NULL;
     status = close(gpsdata->gps_fd);
     gpsdata->gps_fd = -1;
     return status;
-- 
2.8.1