rndc: sync ISC_R_CANCELED handling in callbacks

rndc_recvdone() is not treating the ISC_R_CANCELED result code as a
request to stop data processing, which may cause a crash when trying to
dereference ccmsg->buffer.  Fix by ensuring ISC_R_CANCELED results in an
early exit from rndc_recvdone().

Make sure the logic for handling ISC_R_CANCELED in rndc_recvnonce()
matches the one present in rndc_recvdone() to ensure consistent behavior
between these two sibling functions.

diff --git a/bin/rndc/rndc.c b/bin/rndc/rndc.c
index d31316be83c7baad44a8c24d802bccb08a50dd05..c6e3212f685b90eda994ee1739e6f4922a6900cb 100644 (file)
--- a/bin/rndc/rndc.c
+++ b/bin/rndc/rndc.c
@@ -316,7 +316,7 @@ static void
 rndc_recvdone(isc_nmhandle_t *handle, isc_result_t result, void *arg) {
        isccc_ccmsg_t *ccmsg = (isccc_ccmsg_t *)arg;
        isccc_sexpr_t *response = NULL;
-       isccc_sexpr_t *data;
+       isccc_sexpr_t *data = NULL;
        isccc_region_t source;
        char *errormsg = NULL;
        char *textmsg = NULL;
@@ -339,7 +339,7 @@ rndc_recvdone(isc_nmhandle_t *handle, isc_result_t result, void *arg) {
                      "* the clocks are not synchronized,\n"
                      "* the key signing algorithm is incorrect,\n"
                      "* or the key is invalid.");
-       } else if (result != ISC_R_SUCCESS && result != ISC_R_CANCELED) {
+       } else if (result != ISC_R_SUCCESS) {
                fatal("recv failed: %s", isc_result_totext(result));
        }
 
@@ -414,7 +414,7 @@ rndc_recvnonce(isc_nmhandle_t *handle, isc_result_t result, void *arg) {
 
        REQUIRE(ccmsg != NULL);
 
-       if (shuttingdown && result == ISC_R_EOF) {
+       if (shuttingdown && (result == ISC_R_EOF || result == ISC_R_CANCELED)) {
                atomic_fetch_sub_release(&recvs, 1);
                if (handle != NULL) {
                        REQUIRE(recvnonce_handle == handle);