diff --git a/NEWS b/NEWS
index 36c0cd285..10744d326 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,14 @@
+What's new in Sudo 1.9.11p3
+
+ * Fixed "connection reset" errors on AIX when running shell scripts
+   with the "intercept" or "log_subcmds" sudoers options enabled.
+   Bug #1034.
+
+ * Fixed very slow execution of shell scripts when the "intercept"
+   or "log_subcmds" sudoers options are set on systems that enable
+   Nagle's algorithm on the loopback device, such as AIX.
+   Bug #1034.
+
 What's new in Sudo 1.9.11p2
 
  * Fixed a compilation error on Linux/x86_64 with the x32 ABI.
diff --git a/configure b/configure
index 677458542..2363bb148 100755
--- a/configure
+++ b/configure
@@ -1,6 +1,6 @@
 #! /bin/sh
 # Guess values for system-dependent variables and create Makefiles.
-# Generated by GNU Autoconf 2.71 for sudo 1.9.11p2.
+# Generated by GNU Autoconf 2.71 for sudo 1.9.11p3.
 #
 # Report bugs to <https://bugzilla.sudo.ws/>.
 #
@@ -621,8 +621,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='sudo'
 PACKAGE_TARNAME='sudo'
-PACKAGE_VERSION='1.9.11p2'
-PACKAGE_STRING='sudo 1.9.11p2'
+PACKAGE_VERSION='1.9.11p3'
+PACKAGE_STRING='sudo 1.9.11p3'
 PACKAGE_BUGREPORT='https://bugzilla.sudo.ws/'
 PACKAGE_URL=''
 
@@ -1640,7 +1640,7 @@ if test "$ac_init_help" = "long"; then
   # Omit some internal or obsolete options to make the list less imposing.
   # This message is too long to be a string in the A/UX 3.1 sh.
   cat <<_ACEOF
-\`configure' configures sudo 1.9.11p2 to adapt to many kinds of systems.
+\`configure' configures sudo 1.9.11p3 to adapt to many kinds of systems.
 
 Usage: $0 [OPTION]... [VAR=VALUE]...
 
@@ -1706,7 +1706,7 @@ fi
 
 if test -n "$ac_init_help"; then
   case $ac_init_help in
-     short | recursive ) echo "Configuration of sudo 1.9.11p2:";;
+     short | recursive ) echo "Configuration of sudo 1.9.11p3:";;
    esac
   cat <<\_ACEOF
 
@@ -1996,7 +1996,7 @@ fi
 test -n "$ac_init_help" && exit $ac_status
 if $ac_init_version; then
   cat <<\_ACEOF
-sudo configure 1.9.11p2
+sudo configure 1.9.11p3
 generated by GNU Autoconf 2.71
 
 Copyright (C) 2021 Free Software Foundation, Inc.
@@ -2653,7 +2653,7 @@ cat >config.log <<_ACEOF
 This file contains any messages produced by compilers while
 running configure, to aid debugging if configure makes a mistake.
 
-It was created by sudo $as_me 1.9.11p2, which was
+It was created by sudo $as_me 1.9.11p3, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   $ $0$ac_configure_args_raw
@@ -33050,7 +33050,7 @@ cat >>$CONFIG_STATUS <<\_ACEOF || ac_write_fail=1
 # report actual input values of CONFIG_FILES etc. instead of their
 # values after options handling.
 ac_log="
-This file was extended by sudo $as_me 1.9.11p2, which was
+This file was extended by sudo $as_me 1.9.11p3, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   CONFIG_FILES    = $CONFIG_FILES
@@ -33118,7 +33118,7 @@ ac_cs_config_escaped=`printf "%s\n" "$ac_cs_config" | sed "s/^ //; s/'/'\\\\\\\\
 cat >>$CONFIG_STATUS <<_ACEOF || ac_write_fail=1
 ac_cs_config='$ac_cs_config_escaped'
 ac_cs_version="\\
-sudo config.status 1.9.11p2
+sudo config.status 1.9.11p3
 configured by $0, generated by GNU Autoconf 2.71,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 400700bbe..9f845eddd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -18,7 +18,7 @@ dnl ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
 dnl OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 dnl
 AC_PREREQ([2.70])
-AC_INIT([sudo], [1.9.11p2], [https://bugzilla.sudo.ws/], [sudo])
+AC_INIT([sudo], [1.9.11p3], [https://bugzilla.sudo.ws/], [sudo])
 AC_CONFIG_HEADERS([config.h pathnames.h])
 AC_CONFIG_SRCDIR([src/sudo.c])
 AC_CONFIG_AUX_DIR([scripts])
diff --git a/lib/util/getgrouplist.c b/lib/util/getgrouplist.c
index 96e91089e..125d49460 100644
--- a/lib/util/getgrouplist.c
+++ b/lib/util/getgrouplist.c
@@ -66,7 +66,11 @@ int
 sudo_getgrouplist2_v1(const char *name, GETGROUPS_T basegid,
     GETGROUPS_T **groupsp, int *ngroupsp)
 {
+#ifdef __APPLE__
+    int *groups = (int *)*groupsp;
+#else
     GETGROUPS_T *groups = *groupsp;
+#endif
     int ngroups;
 #ifndef HAVE_GETGROUPLIST_2
     int grpsize, tries;
diff --git a/plugins/sudoers/logging.c b/plugins/sudoers/logging.c
index d681b8253..286c6aee8 100644
--- a/plugins/sudoers/logging.c
+++ b/plugins/sudoers/logging.c
@@ -573,15 +573,15 @@ log_allowed(struct eventlog *evlog)
 }
 
 bool
-log_exit_status(int exit_status)
+log_exit_status(int status)
 {
     struct eventlog evlog;
     int evl_flags = 0;
-    int ecode = 0;
+    int exit_value = 0;
     int oldlocale;
     struct timespec run_time;
     char sigbuf[SIG2STR_MAX];
-    char *signame = NULL;
+    char *signal_name = NULL;
     bool dumped_core = false;
     bool ret = true;
     debug_decl(log_exit_status, SUDOERS_DEBUG_LOGGING);
@@ -594,17 +594,17 @@ log_exit_status(int exit_status)
 	}
 	sudo_timespecsub(&run_time, &sudo_user.submit_time, &run_time);
 
-        if (WIFEXITED(exit_status)) {
-	    ecode = WEXITSTATUS(exit_status);
-        } else if (WIFSIGNALED(exit_status)) {
-            int signo = WTERMSIG(exit_status);
+        if (WIFEXITED(status)) {
+	    exit_value = WEXITSTATUS(status);
+        } else if (WIFSIGNALED(status)) {
+            int signo = WTERMSIG(status);
             if (signo <= 0 || sig2str(signo, sigbuf) == -1)
                 (void)snprintf(sigbuf, sizeof(sigbuf), "%d", signo);
-	    signame = sigbuf;
-	    ecode = signo | 128;
-	    dumped_core = WCOREDUMP(exit_status);
+	    signal_name = sigbuf;
+	    exit_value = signo | 128;
+	    dumped_core = WCOREDUMP(status);
         } else {
-            sudo_warnx("invalid exit status 0x%x", exit_status);
+            sudo_warnx("invalid exit status 0x%x", status);
 	    ret = false;
 	    goto done;
         }
@@ -619,8 +619,8 @@ log_exit_status(int exit_status)
 		SET(evl_flags, EVLOG_MAIL_ONLY);
 	}
 	evlog.run_time = run_time;
-	evlog.exit_value = ecode;
-	evlog.signal_name = signame;
+	evlog.exit_value = exit_value;
+	evlog.signal_name = signal_name;
 	evlog.dumped_core = dumped_core;
 	if (!eventlog_exit(&evlog, evl_flags))
 	    ret = false;
diff --git a/src/exec_intercept.c b/src/exec_intercept.c
index 3f7064aea..6560d93cf 100644
--- a/src/exec_intercept.c
+++ b/src/exec_intercept.c
@@ -25,6 +25,7 @@
 
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <netinet/tcp.h>
 
 #if defined(HAVE_STDINT_H)
 # include <stdint.h>
@@ -560,8 +561,12 @@ intercept_read(int fd, struct intercept_closure *closure)
 	case false:
 	    goto done;
 	default:
-	    if (errno == EINTR || errno == EAGAIN)
+	    if (errno == EINTR || errno == EAGAIN) {
 		debug_return_bool(true);
+		sudo_debug_printf(
+		    SUDO_DEBUG_WARN|SUDO_DEBUG_ERRNO|SUDO_DEBUG_LINENO,
+		    "reading intercept token");
+	    }
 	    sudo_warn("recv");
 	    goto done;
 	}
@@ -574,8 +579,12 @@ intercept_read(int fd, struct intercept_closure *closure)
 	nread = recv(fd, &req_len, sizeof(req_len), 0);
 	if (nread != sizeof(req_len)) {
 	    if (nread == -1) {
-		if (errno == EINTR || errno == EAGAIN)
+		if (errno == EINTR || errno == EAGAIN) {
+		    sudo_debug_printf(
+			SUDO_DEBUG_WARN|SUDO_DEBUG_ERRNO|SUDO_DEBUG_LINENO,
+			"reading intercept message size");
 		    debug_return_bool(true);
+		}
 		sudo_warn("recv");
 	    }
 	    goto done;
@@ -605,8 +614,12 @@ intercept_read(int fd, struct intercept_closure *closure)
 	/* EOF, other side must have exited. */
 	goto done;
     case -1:
-	if (errno == EINTR || errno == EAGAIN)
+	if (errno == EINTR || errno == EAGAIN) {
+	    sudo_debug_printf(
+		SUDO_DEBUG_WARN|SUDO_DEBUG_ERRNO|SUDO_DEBUG_LINENO,
+		"reading intercept message");
 	    debug_return_bool(true);
+	}
 	sudo_warn("recv");
 	goto done;
     default:
@@ -835,8 +848,12 @@ intercept_write(int fd, struct intercept_closure *closure)
     nwritten = send(fd, closure->buf + closure->off,
 	closure->len - closure->off, 0);
     if (nwritten == -1) {
-	if (errno == EINTR || errno == EAGAIN)
+	if (errno == EINTR || errno == EAGAIN) {
+	    sudo_debug_printf(
+		SUDO_DEBUG_WARN|SUDO_DEBUG_ERRNO|SUDO_DEBUG_LINENO,
+		"writing intercept message");
 	    debug_return_bool(true);
+	}
 	sudo_warn("send");
 	goto done;
     }
@@ -930,7 +947,7 @@ intercept_accept_cb(int fd, int what, void *v)
     struct sudo_event_base *evbase = sudo_ev_get_base(&closure->ev);
     struct sockaddr_in sin;
     socklen_t sin_len = sizeof(sin);
-    int client_sock, flags;
+    int client_sock, flags, on = 1;
     debug_decl(intercept_accept_cb, SUDO_DEBUG_EXEC);
 
     if (closure->state != RECV_CONNECTION) {
@@ -951,6 +968,9 @@ intercept_accept_cb(int fd, int what, void *v)
     if (flags != -1)
 	(void)fcntl(client_sock, F_SETFL, flags | O_NONBLOCK);
 
+    /* Send data immediately, we need low latency IPC. */
+    (void)setsockopt(client_sock, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on));
+
     /*
      * Create a new intercept closure and register an event for client_sock.
      */
diff --git a/src/sudo_intercept_common.c b/src/sudo_intercept_common.c
index 0702b8c81..e6431882b 100644
--- a/src/sudo_intercept_common.c
+++ b/src/sudo_intercept_common.c
@@ -26,6 +26,7 @@
 #include <sys/types.h>
 #include <sys/socket.h>
 #include <netinet/in.h>
+#include <netinet/tcp.h>
 
 #if defined(HAVE_STDINT_H)
 # include <stdint.h>
@@ -136,16 +137,29 @@ recv_intercept_response(int fd)
     debug_decl(recv_intercept_response, SUDO_DEBUG_EXEC);
 
     /* Read message size (uint32_t in host byte order). */
-    nread = recv(fd, &res_len, sizeof(res_len), 0);
-    if ((size_t)nread != sizeof(res_len)) {
-        if (nread == 0) {
+    for (;;) {
+	nread = recv(fd, &res_len, sizeof(res_len), 0);
+	if (nread == ssizeof(res_len))
+	    break;
+	switch (nread) {
+	case 0:
 	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
 		"unexpected EOF reading response size");
-	} else {
-	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO,
+	    break;
+	case -1:
+	    if (errno == EINTR)
+		continue;
+	    sudo_debug_printf(
+		SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO,
 		"error reading response size");
+	    break;
+	default:
+	    sudo_debug_printf(
+		SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
+		"error reading response size: short read");
+	    break;
 	}
-        goto done;
+	goto done;
     }
     if (res_len > MESSAGE_SIZE_MAX) {
 	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
@@ -169,7 +183,8 @@ recv_intercept_response(int fd)
 	case -1:
 	    if (errno == EINTR)
 		continue;
-	    sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO,
+	    sudo_debug_printf(
+		SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO|SUDO_DEBUG_ERRNO,
 		"error reading response");
 	    goto done;
 	default:
@@ -199,7 +214,7 @@ sudo_interposer_init(void)
 {
     InterceptResponse *res = NULL;
     static bool initialized;
-    int fd = -1;
+    int flags, fd = -1;
     char **p;
     debug_decl(sudo_interposer_init, SUDO_DEBUG_EXEC);
 
@@ -239,6 +254,13 @@ sudo_interposer_init(void)
 	goto done;
     }
 
+    /*
+     * We don't want to use non-blocking I/O.
+     */
+    flags = fcntl(fd, F_GETFL, 0);
+    if (flags != -1)
+        (void)fcntl(fd, F_SETFL, flags & ~O_NONBLOCK);
+
     /*
      * Send InterceptHello message to over the fd.
      */
@@ -334,6 +356,7 @@ static int
 intercept_connect(void)
 {
     int sock = -1;
+    int on = 1;
     struct sockaddr_in sin;
     debug_decl(command_allowed, SUDO_DEBUG_EXEC);
 
@@ -353,6 +376,9 @@ intercept_connect(void)
 	goto done;
     }
 
+    /* Send data immediately, we need low latency IPC. */
+    (void)setsockopt(sock, IPPROTO_TCP, TCP_NODELAY, &on, sizeof(on));
+
     if (connect(sock, (struct sockaddr *)&sin, sizeof(sin)) == -1) {
 	sudo_warn("connect");
 	close(sock);