Merge sudo 1.9.11p1 from tip.SUDO_1_9_11p1

17 files changed, 117 insertions, 89 deletions

diff --git a/NEWS b/NEWS
index b6251fc24..9700b0200 100644
--- a/NEWS
+++ b/NEWS
@@ -1,3 +1,19 @@
+What's new in Sudo 1.9.11p1
+
+ * Correctly handle EAGAIN in the I/O read/right events.  This fixes
+   a hang seen on some systems when piping a large amount of data
+   through sudo, such as via rsync.  Bug #963.
+
+ * Changes to avoid implementation or unspecified behavior when
+   bit shifting signed values in the protobuf library.
+
+ * Fixed a compilation error on Linux/aarch64.
+
+ * Fixed the configure check for seccomp(2) support on Linux.
+
+ * Corrected the EBNF specification for tags in the sudoers manual
+   page.  GitHub issue #153.
+
 What's new in Sudo 1.9.11
 
  * Fixed a crash in the Python module with Python 3.9.10 on some
diff --git a/config.h.in b/config.h.in
index d0be95822..c9c024a15 100644
--- a/config.h.in
+++ b/config.h.in
@@ -175,9 +175,9 @@
    don't. */
 #undef HAVE_DECL_QUAD_MIN
 
-/* Define to 1 if you have the declaration of `SECCOMP_SET_MODE_FILTER', and
-   to 0 if you don't. */
-#undef HAVE_DECL_SECCOMP_SET_MODE_FILTER
+/* Define to 1 if you have the declaration of `SECCOMP_MODE_FILTER', and to 0
+   if you don't. */
+#undef HAVE_DECL_SECCOMP_MODE_FILTER
 
 /* Define to 1 if you have the declaration of `setauthdb', and to 0 if you
    don't. */
diff --git a/configure b/configure
index 33182d022..14d14976d 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 1.9.11.
+# Generated by GNU Autoconf 2.71 for sudo 1.9.11p1.
 #
 # Report bugs to <https://bugzilla.sudo.ws/>.
 #
@@ -621,8 +621,8 @@ MAKEFLAGS=
 # Identity of this package.
 PACKAGE_NAME='sudo'
 PACKAGE_TARNAME='sudo'
-PACKAGE_VERSION='1.9.11'
-PACKAGE_STRING='sudo 1.9.11'
+PACKAGE_VERSION='1.9.11p1'
+PACKAGE_STRING='sudo 1.9.11p1'
 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 1.9.11 to adapt to many kinds of systems.
+\`configure' configures sudo 1.9.11p1 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 1.9.11:";;
+     short | recursive ) echo "Configuration of sudo 1.9.11p1:";;
    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 1.9.11
+sudo configure 1.9.11p1
 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 1.9.11, which was
+It was created by sudo $as_me 1.9.11p1, which was
 generated by GNU Autoconf 2.71.  Invocation command line was
 
   $ $0$ac_configure_args_raw
@@ -17821,8 +17821,8 @@ fi
     *-*-linux*|*-*-k*bsd*-gnu)
 		shadow_funcs="getspnam"
 		test -z "$with_pam" && AUTH_EXCL_DEF="PAM"
-		# Check for SECCOMP_SET_MODE_FILTER in linux/seccomp.h
-		ac_fn_check_decl "$LINENO" "SECCOMP_SET_MODE_FILTER" "ac_cv_have_decl_SECCOMP_SET_MODE_FILTER" "
+		# Check for SECCOMP_MODE_FILTER in linux/seccomp.h
+		ac_fn_check_decl "$LINENO" "SECCOMP_MODE_FILTER" "ac_cv_have_decl_SECCOMP_MODE_FILTER" "
 #include <sys/types.h>
 #include <sys/prctl.h>
 #include <asm/unistd.h>
@@ -17830,13 +17830,13 @@ fi
 #include <linux/filter.h>
 
 " "$ac_c_undeclared_builtin_options" "CFLAGS"
-if test "x$ac_cv_have_decl_SECCOMP_SET_MODE_FILTER" = xyes
+if test "x$ac_cv_have_decl_SECCOMP_MODE_FILTER" = xyes
 then :
   ac_have_decl=1
 else $as_nop
   ac_have_decl=0
 fi
-printf "%s\n" "#define HAVE_DECL_SECCOMP_SET_MODE_FILTER $ac_have_decl" >>confdefs.h
+printf "%s\n" "#define HAVE_DECL_SECCOMP_MODE_FILTER $ac_have_decl" >>confdefs.h
 
 		# We call getrandom via syscall(3) in case it is not in libc
 		ac_fn_c_check_header_compile "$LINENO" "linux/random.h" "ac_cv_header_linux_random_h" "$ac_includes_default"
@@ -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 1.9.11, which was
+This file was extended by sudo $as_me 1.9.11p1, 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 1.9.11
+sudo config.status 1.9.11p1
 configured by $0, generated by GNU Autoconf 2.71,
   with options \\"\$ac_cs_config\\"
 
diff --git a/configure.ac b/configure.ac
index 4d4278f81..fc4abf8a5 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], [1.9.11], [https://bugzilla.sudo.ws/], [sudo])
+AC_INIT([sudo], [1.9.11p1], [https://bugzilla.sudo.ws/], [sudo])
 AC_CONFIG_HEADERS([config.h pathnames.h])
 AC_CONFIG_SRCDIR([src/sudo.c])
 AC_CONFIG_AUX_DIR([scripts])
@@ -2065,8 +2065,8 @@ case "$host" in
     *-*-linux*|*-*-k*bsd*-gnu)
 		shadow_funcs="getspnam"
 		test -z "$with_pam" && AUTH_EXCL_DEF="PAM"
-		# Check for SECCOMP_SET_MODE_FILTER in linux/seccomp.h
-		AC_CHECK_DECLS([SECCOMP_SET_MODE_FILTER], [], [], [
+		# Check for SECCOMP_MODE_FILTER in linux/seccomp.h
+		AC_CHECK_DECLS([SECCOMP_MODE_FILTER], [], [], [
 #include <sys/types.h>
 #include <sys/prctl.h>
 #include <asm/unistd.h>
diff --git a/docs/sudoers.man.in b/docs/sudoers.man.in
index e12462665..5f73f7ca2 100644
--- a/docs/sudoers.man.in
+++ b/docs/sudoers.man.in
@@ -1273,7 +1273,7 @@ User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \e
 Cmnd_Spec_List ::= Cmnd_Spec |
                    Cmnd_Spec ',' Cmnd_Spec_List
 
-Cmnd_Spec ::= Runas_Spec? Option_Spec* Tag_Spec* Cmnd
+Cmnd_Spec ::= Runas_Spec? Option_Spec* (Tag_Spec ':')* Cmnd
 
 Runas_Spec ::= '(' Runas_List? (':' Runas_List)? ')'
 
@@ -1304,11 +1304,11 @@ Chdir_Spec ::= 'CWD=directory'
 
 Chroot_Spec ::= 'CHROOT=directory'
 
-Tag_Spec ::= ('EXEC:' | 'NOEXEC:' | 'FOLLOW:' | 'NOFOLLOW' |
-              'LOG_INPUT:' | 'NOLOG_INPUT:' | 'LOG_OUTPUT:' |
-              'NOLOG_OUTPUT:' | 'MAIL:' | 'NOMAIL:' | 'INTERCEPT:' |
-              'NOINTERCEPT:' | 'PASSWD:' | 'NOPASSWD:' | 'SETENV:' |
-              'NOSETENV:')
+Tag_Spec ::= ('EXEC' | 'NOEXEC' | 'FOLLOW' | 'NOFOLLOW' |
+              'LOG_INPUT' | 'NOLOG_INPUT' | 'LOG_OUTPUT' |
+              'NOLOG_OUTPUT' | 'MAIL' | 'NOMAIL' | 'INTERCEPT' |
+              'NOINTERCEPT' | 'PASSWD' | 'NOPASSWD' | 'SETENV' |
+              'NOSETENV')
 .RE
 .fi
 .PP
diff --git a/docs/sudoers.mdoc.in b/docs/sudoers.mdoc.in
index 9211fbe9e..29aeacfdd 100644
--- a/docs/sudoers.mdoc.in
+++ b/docs/sudoers.mdoc.in
@@ -1223,7 +1223,7 @@ User_Spec ::= User_List Host_List '=' Cmnd_Spec_List \e
 Cmnd_Spec_List ::= Cmnd_Spec |
                    Cmnd_Spec ',' Cmnd_Spec_List
 
-Cmnd_Spec ::= Runas_Spec? Option_Spec* Tag_Spec* Cmnd
+Cmnd_Spec ::= Runas_Spec? Option_Spec* (Tag_Spec ':')* Cmnd
 
 Runas_Spec ::= '(' Runas_List? (':' Runas_List)? ')'
 
@@ -1262,11 +1262,11 @@ Chdir_Spec ::= 'CWD=directory'
 
 Chroot_Spec ::= 'CHROOT=directory'
 
-Tag_Spec ::= ('EXEC:' | 'NOEXEC:' | 'FOLLOW:' | 'NOFOLLOW' |
-              'LOG_INPUT:' | 'NOLOG_INPUT:' | 'LOG_OUTPUT:' |
-              'NOLOG_OUTPUT:' | 'MAIL:' | 'NOMAIL:' | 'INTERCEPT:' |
-              'NOINTERCEPT:' | 'PASSWD:' | 'NOPASSWD:' | 'SETENV:' |
-              'NOSETENV:')
+Tag_Spec ::= ('EXEC' | 'NOEXEC' | 'FOLLOW' | 'NOFOLLOW' |
+              'LOG_INPUT' | 'NOLOG_INPUT' | 'LOG_OUTPUT' |
+              'NOLOG_OUTPUT' | 'MAIL' | 'NOMAIL' | 'INTERCEPT' |
+              'NOINTERCEPT' | 'PASSWD' | 'NOPASSWD' | 'SETENV' |
+              'NOSETENV')
 .Ed
 .Pp
 A
diff --git a/include/sudo_event.h b/include/sudo_event.h
index 2bb7bb2be..12bb89478 100644
--- a/include/sudo_event.h
+++ b/include/sudo_event.h
@@ -102,10 +102,10 @@ struct sudo_event_base {
     int pfd_high;		/* highest slot used */
     int pfd_free;		/* idx of next free entry or pfd_max if full */
 #else
-    fd_set *readfds_in;		/* read I/O descriptor set (in) */
-    fd_set *writefds_in;	/* write I/O descriptor set (in) */
-    fd_set *readfds_out;	/* read I/O descriptor set (out) */
-    fd_set *writefds_out;	/* write I/O descriptor set (out) */
+    void *readfds_in;		/* read I/O descriptor set (in) */
+    void *writefds_in;		/* write I/O descriptor set (in) */
+    void *readfds_out;		/* read I/O descriptor set (out) */
+    void *writefds_out;		/* write I/O descriptor set (out) */
     int maxfd;			/* max fd we can store in readfds/writefds */
     int highfd;			/* highest fd to pass as 1st arg to select */
 #endif /* HAVE_POLL */
diff --git a/lib/protobuf-c/protobuf-c.c b/lib/protobuf-c/protobuf-c.c
index 96b750650..9d56e1fec 100644
--- a/lib/protobuf-c/protobuf-c.c
+++ b/lib/protobuf-c/protobuf-c.c
@@ -331,9 +331,8 @@ int32_size(int32_t v)
 static inline uint32_t
 zigzag32(int32_t v)
 {
-	// Note:  the right-shift must be arithmetic
-	// Note:  left shift must be unsigned because of overflow
-	return ((uint32_t)(v) << 1) ^ (uint32_t)(v >> 31);
+	// Note:  Using unsigned types prevents undefined behavior
+	return ((uint32_t)v << 1) ^ -((uint32_t)v >> 31);
 }
 
 /**
@@ -395,9 +394,8 @@ uint64_size(uint64_t v)
 static inline uint64_t
 zigzag64(int64_t v)
 {
-	// Note:  the right-shift must be arithmetic
-	// Note:  left shift must be unsigned because of overflow
-	return ((uint64_t)(v) << 1) ^ (uint64_t)(v >> 63);
+	// Note:  Using unsigned types prevents undefined behavior
+	return ((uint64_t)v << 1) ^ -((uint64_t)v >> 63);
 }
 
 /**
@@ -817,7 +815,8 @@ uint32_pack(uint32_t value, uint8_t *out)
 }
 
 /**
- * Pack a signed 32-bit integer and return the number of bytes written.
+ * Pack a signed 32-bit integer and return the number of bytes written,
+ * passed as unsigned to avoid implementation-specific behavior.
  * Negative numbers are encoded as two's complement 64-bit integers.
  *
  * \param value
@@ -828,14 +827,14 @@ uint32_pack(uint32_t value, uint8_t *out)
  *      Number of bytes written to `out`.
  */
 static inline size_t
-int32_pack(int32_t value, uint8_t *out)
+int32_pack(uint32_t value, uint8_t *out)
 {
-	if (value < 0) {
+	if ((int32_t)value < 0) {
 		out[0] = value | 0x80;
 		out[1] = (value >> 7) | 0x80;
 		out[2] = (value >> 14) | 0x80;
 		out[3] = (value >> 21) | 0x80;
-		out[4] = (value >> 28) | 0x80;
+		out[4] = (value >> 28) | 0xf0;
 		out[5] = out[6] = out[7] = out[8] = 0xff;
 		out[9] = 0x01;
 		return 10;
@@ -2440,7 +2439,7 @@ static inline int32_t
 unzigzag32(uint32_t v)
 {
 	// Note:  Using unsigned types prevents undefined behavior
-	return (int32_t)((v >> 1) ^ (~(v & 1) + 1));
+	return (int32_t)((v >> 1) ^ -(v & 1));
 }
 
 static inline uint32_t
@@ -2482,7 +2481,7 @@ static inline int64_t
 unzigzag64(uint64_t v)
 {
 	// Note:  Using unsigned types prevents undefined behavior
-	return (int64_t)((v >> 1) ^ (~(v & 1) + 1));
+	return (int64_t)((v >> 1) ^ -(v & 1));
 }
 
 static inline uint64_t
@@ -2619,11 +2618,14 @@ parse_required_member(ScannedMember *scanned_member,
 			return FALSE;
 
 		def_mess = scanned_member->field->default_value;
-		subm = protobuf_c_message_unpack(scanned_member->field->descriptor,
-						 allocator,
-						 len - pref_len,
-						 data + pref_len);
-
+		if (len > pref_len) {
+			subm = protobuf_c_message_unpack(scanned_member->field->descriptor,
+							 allocator,
+							 len - pref_len,
+							 data + pref_len);
+		} else {
+			subm = NULL;
+		}
 		if (maybe_clear &&
 		    *pmessage != NULL &&
 		    *pmessage != def_mess)
@@ -3553,7 +3555,7 @@ protobuf_c_service_generated_init(ProtobufCService *service,
 	service->descriptor = descriptor;
 	service->destroy = destroy;
 	service->invoke = protobuf_c_service_invoke_internal;
-	memset(service + 1, 0, descriptor->n_methods * sizeof(GenericHandler));
+	memset(&service[1], 0, descriptor->n_methods * sizeof(GenericHandler));
 }
 
 void protobuf_c_service_destroy(ProtobufCService *service)
diff --git a/lib/util/event_select.c b/lib/util/event_select.c
index a2ee9d1b3..8d3e8a9b2 100644
--- a/lib/util/event_select.c
+++ b/lib/util/event_select.c
@@ -120,12 +120,12 @@ sudo_ev_add_impl(struct sudo_event_base *base, struct sudo_event *ev)
     if (ISSET(ev->events, SUDO_EV_READ)) {
 	sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: added fd %d to readfs",
 	    __func__, ev->fd);
-	FD_SET(ev->fd, base->readfds_in);
+	FD_SET(ev->fd, (fd_set *)base->readfds_in);
     }
     if (ISSET(ev->events, SUDO_EV_WRITE)) {
 	sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: added fd %d to writefds",
 	    __func__, ev->fd);
-	FD_SET(ev->fd, base->writefds_in);
+	FD_SET(ev->fd, (fd_set *)base->writefds_in);
     }
     if (ev->fd > base->highfd)
 	base->highfd = ev->fd;
@@ -142,17 +142,17 @@ sudo_ev_del_impl(struct sudo_event_base *base, struct sudo_event *ev)
     if (ISSET(ev->events, SUDO_EV_READ)) {
 	sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: removed fd %d from readfds",
 	    __func__, ev->fd);
-	FD_CLR(ev->fd, base->readfds_in);
+	FD_CLR(ev->fd, (fd_set *)base->readfds_in);
     }
     if (ISSET(ev->events, SUDO_EV_WRITE)) {
 	sudo_debug_printf(SUDO_DEBUG_DEBUG, "%s: removed fd %d from writefds",
 	    __func__, ev->fd);
-	FD_CLR(ev->fd, base->writefds_in);
+	FD_CLR(ev->fd, (fd_set *)base->writefds_in);
     }
     if (base->highfd == ev->fd) {
 	for (;;) {
-	    if (FD_ISSET(base->highfd, base->readfds_in) ||
-		FD_ISSET(base->highfd, base->writefds_in))
+	    if (FD_ISSET(base->highfd, (fd_set *)base->readfds_in) ||
+		FD_ISSET(base->highfd, (fd_set *)base->writefds_in))
 		break;
 	    if (--base->highfd < 0)
 		break;
@@ -230,9 +230,9 @@ sudo_ev_scan_impl(struct sudo_event_base *base, int flags)
 	TAILQ_FOREACH(ev, &base->events, entries) {
 	    if (ev->fd >= 0) {
 		int what = 0;
-		if (FD_ISSET(ev->fd, base->readfds_out))
+		if (FD_ISSET(ev->fd, (fd_set *)base->readfds_out))
 		    what |= (ev->events & SUDO_EV_READ);
-		if (FD_ISSET(ev->fd, base->writefds_out))
+		if (FD_ISSET(ev->fd, (fd_set *)base->writefds_out))
 		    what |= (ev->events & SUDO_EV_WRITE);
 		if (what != 0) {
 		    /* Make event active. */
diff --git a/logsrvd/logsrvd.c b/logsrvd/logsrvd.c
index 4eba07e07..4bf739ff5 100644
--- a/logsrvd/logsrvd.c
+++ b/logsrvd/logsrvd.c
@@ -929,6 +929,8 @@ server_msg_cb(int fd, int what, void *v)
     }
 
     if (nwritten == -1) {
+	if (errno == EAGAIN || errno == EINTR)
+	    debug_return;
 	sudo_warn("%s: write", closure->ipaddr);
 	goto finished;
     }
@@ -1043,7 +1045,7 @@ client_msg_cb(int fd, int what, void *v)
 	__func__, nread, closure->ipaddr);
     switch (nread) {
     case -1:
-	if (errno == EAGAIN)
+	if (errno == EAGAIN || errno == EINTR)
 	    debug_return;
 	sudo_warn("%s: read", closure->ipaddr);
 	goto close_connection;
@@ -1519,9 +1521,10 @@ listener_cb(int fd, int what, void *v)
 		"unable to start new connection");
 	}
     } else {
-	if (errno != EAGAIN)
-	    sudo_warn("accept");
+	if (errno == EAGAIN || errno == EINTR)
+	    debug_return;
 	/* TODO: pause accepting on ENFILE and EMFILE */
+	sudo_warn("accept");
     }
 
     debug_return;
diff --git a/logsrvd/logsrvd_relay.c b/logsrvd/logsrvd_relay.c
index f23b88f90..6937ed82c 100644
--- a/logsrvd/logsrvd_relay.c
+++ b/logsrvd/logsrvd_relay.c
@@ -799,7 +799,7 @@ relay_server_msg_cb(int fd, int what, void *v)
 	relay_closure->relay_name.name, relay_closure->relay_name.ipaddr);
     switch (nread) {
     case -1:
-	if (errno == EAGAIN)
+	if (errno == EAGAIN || errno == EINTR)
 	    debug_return;
 	sudo_warn("%s: read", relay_closure->relay_name.ipaddr);
 	closure->errstr = _("unable to read from relay");
@@ -970,6 +970,8 @@ relay_client_msg_cb(int fd, int what, void *v)
     {
 	nwritten = write(fd, buf->data + buf->off, buf->len - buf->off);
 	if (nwritten == -1) {
+	    if (errno == EAGAIN || errno == EINTR)
+		debug_return;
 	    sudo_warn("%s: write", relay_closure->relay_name.ipaddr);
 	    closure->errstr = _("error writing to relay");
 	    goto send_error;
diff --git a/logsrvd/sendlog.c b/logsrvd/sendlog.c
index 094bd369d..50d7f59c1 100644
--- a/logsrvd/sendlog.c
+++ b/logsrvd/sendlog.c
@@ -1359,7 +1359,7 @@ server_msg_cb(int fd, int what, void *v)
 	__func__, nread);
     switch (nread) {
     case -1:
-	if (errno == EAGAIN)
+	if (errno == EAGAIN || errno == EINTR)
 	    debug_return;
 	sudo_warn("recv");
 	goto bad;
@@ -1479,6 +1479,8 @@ client_msg_cb(int fd, int what, void *v)
 	nwritten = send(fd, buf->data + buf->off, buf->len - buf->off, 0);
     }
     if (nwritten == -1) {
+	if (errno == EAGAIN || errno == EINTR)
+	    debug_return;
 	sudo_warn("send");
 	goto bad;
     }
diff --git a/plugins/sudoers/sudoers.in b/plugins/sudoers/sudoers.in
index a0d293409..5efda5d23 100644
--- a/plugins/sudoers/sudoers.in
+++ b/plugins/sudoers/sudoers.in
@@ -64,7 +64,7 @@
 ##
 ## Uncomment to enable logging of a command's output, except for
 ## sudoreplay and reboot.  Use sudoreplay to play back logged sessions.
-## Sudo will create up to 2,176,782,336 I/O logs before recycing them.
+## Sudo will create up to 2,176,782,336 I/O logs before recycling them.
 ## Set maxseq to a smaller number if you don't have unlimited disk space.
 # Defaults log_output
 # Defaults!/usr/bin/sudoreplay !log_output
diff --git a/src/exec_ptrace.h b/src/exec_ptrace.h
index 7f26283a8..4a5a86581 100644
--- a/src/exec_ptrace.h
+++ b/src/exec_ptrace.h
@@ -76,6 +76,7 @@
 # define reg_arg4(x)		(x).r10
 #elif defined(__aarch64__)
 # define SECCOMP_AUDIT_ARCH	AUDIT_ARCH_AARCH64
+# define sudo_pt_regs		struct user_pt_regs
 # define reg_syscall(x)		(x).regs[8]	/* w8 */
 # define reg_retval(x)		(x).regs[0]	/* x0 */
 # define reg_sp(x)		(x).sp		/* sp */
diff --git a/src/exec_pty.c b/src/exec_pty.c
index 326d8318a..e2fd9c60e 100644
--- a/src/exec_pty.c
+++ b/src/exec_pty.c
@@ -676,9 +676,11 @@ read_callback(int fd, int what, void *v)
 		/* Schedule SIGTTIN to be forwarded to the command. */
 		schedule_signal(iob->ec, SIGTTIN);
 	    }
-	    if (errno == EAGAIN || errno == EINTR)
+	    if (errno == EAGAIN || errno == EINTR) {
+		/* Not an error, retry later. */
 		break;
-	    /* treat read error as fatal and close the fd */
+	    }
+	    /* Treat read error as fatal and close the fd. */
 	    sudo_debug_printf(SUDO_DEBUG_ERROR,
 		"error reading fd %d: %s", fd, strerror(errno));
 	    FALLTHROUGH;
@@ -705,18 +707,18 @@ read_callback(int fd, int what, void *v)
 		iob->ec->cmnd_pid = -1;
 	    }
 	    iob->len += n;
-	    /* Enable writer now that there is data in the buffer. */
+	    /* Disable reader if buffer is full. */
+	    if (iob->len == sizeof(iob->buf))
+		sudo_ev_del(evbase, iob->revent);
+	    /* Enable writer now that there is new data in the buffer. */
 	    if (iob->wevent != NULL) {
 		if (sudo_ev_add(evbase, iob->wevent, NULL, false) == -1)
 		    sudo_fatal("%s", U_("unable to add event to queue"));
 	    }
-	    /* Re-enable reader if buffer is not full. */
-	    if (iob->len != sizeof(iob->buf)) {
-		if (sudo_ev_add(evbase, iob->revent, NULL, false) == -1)
-		    sudo_fatal("%s", U_("unable to add event to queue"));
-	    }
 	    break;
     }
+
+    debug_return;
 }
 
 /*
@@ -783,7 +785,7 @@ write_callback(int fd, int what, void *v)
 	    }
 	    FALLTHROUGH;
 	case EAGAIN:
-	    /* not an error */
+	    /* Not an error, retry later. */
 	    break;
 	default:
 	    /* XXX - need a way to distinguish non-exec error. */
@@ -798,20 +800,16 @@ write_callback(int fd, int what, void *v)
 	sudo_debug_printf(SUDO_DEBUG_INFO,
 	    "wrote %zd bytes to fd %d", n, fd);
 	iob->off += n;
-	/* Reset buffer if fully consumed. */
+	/* Disable writer and reset the buffer if fully consumed. */
 	if (iob->off == iob->len) {
 	    iob->off = iob->len = 0;
+	    sudo_ev_del(evbase, iob->wevent);
 	    /* Forward the EOF from reader to writer. */
 	    if (iob->revent == NULL) {
 		safe_close(fd);
 		ev_free_by_fd(evbase, fd);
 	    }
 	}
-	/* Re-enable writer if buffer is not empty. */
-	if (iob->len > iob->off) {
-	    if (sudo_ev_add(evbase, iob->wevent, NULL, false) == -1)
-		sudo_fatal("%s", U_("unable to add event to queue"));
-	}
 	/* Enable reader if buffer is not full. */
 	if (iob->revent != NULL &&
 	    (ttymode == TERM_RAW || !USERTTY_EVENT(iob->revent))) {
@@ -821,6 +819,8 @@ write_callback(int fd, int what, void *v)
 	    }
 	}
     }
+
+    debug_return;
 }
 
 static void
@@ -844,8 +844,10 @@ io_buf_new(int rfd, int wfd,
     if ((iob = malloc(sizeof(*iob))) == NULL)
 	sudo_fatalx(U_("%s: %s"), __func__, U_("unable to allocate memory"));
     iob->ec = ec;
-    iob->revent = sudo_ev_alloc(rfd, SUDO_EV_READ, read_callback, iob);
-    iob->wevent = sudo_ev_alloc(wfd, SUDO_EV_WRITE, write_callback, iob);
+    iob->revent = sudo_ev_alloc(rfd, SUDO_EV_READ|SUDO_EV_PERSIST,
+	read_callback, iob);
+    iob->wevent = sudo_ev_alloc(wfd, SUDO_EV_WRITE|SUDO_EV_PERSIST,
+	write_callback, iob);
     iob->len = 0;
     iob->off = 0;
     iob->action = action;
diff --git a/src/sudo_exec.h b/src/sudo_exec.h
index d225524d5..2f099a332 100644
--- a/src/sudo_exec.h
+++ b/src/sudo_exec.h
@@ -95,13 +95,13 @@ union sudo_token_un {
  * On MIPS we can't change the syscall return and only support log_subcmds.
  */
 #if defined(_PATH_SUDO_INTERCEPT) && defined(__linux__)
-# if defined(HAVE_DECL_SECCOMP_SET_MODE_FILTER) && HAVE_DECL_SECCOMP_SET_MODE_FILTER
+# if defined(HAVE_DECL_SECCOMP_MODE_FILTER) && HAVE_DECL_SECCOMP_MODE_FILTER
 #  if defined(__x86_64__) || defined(__i386__) || defined(__aarch64__) || defined(__arm__) || defined(__mips__) || defined(__powerpc__) || (defined(__riscv) && __riscv_xlen == 64) || defined(__s390__)
 #   ifndef HAVE_PTRACE_INTERCEPT
 #    define HAVE_PTRACE_INTERCEPT 1
 #   endif /* HAVE_PTRACE_INTERCEPT */
 #  endif /* __amd64__ || __i386__ || __aarch64__ || __riscv || __s390__ */
-# endif /* HAVE_DECL_SECCOMP_SET_MODE_FILTER */
+# endif /* HAVE_DECL_SECCOMP_MODE_FILTER */
 #endif /* _PATH_SUDO_INTERCEPT && __linux__ */
 
 /*
diff --git a/src/sudo_noexec.c b/src/sudo_noexec.c
index 3a2abdfdd..fd8117226 100644
--- a/src/sudo_noexec.c
+++ b/src/sudo_noexec.c
@@ -25,7 +25,7 @@
 
 #include <sys/types.h>
 
-#if defined(HAVE_DECL_SECCOMP_SET_MODE_FILTER) && HAVE_DECL_SECCOMP_SET_MODE_FILTER
+#if defined(HAVE_DECL_SECCOMP_MODE_FILTER) && HAVE_DECL_SECCOMP_MODE_FILTER
 # include <sys/prctl.h>
 # include <asm/unistd.h>
 # include <linux/filter.h>
@@ -213,7 +213,7 @@ INTERPOSE(wordexp)
 /*
  * On Linux we can use a seccomp() filter to disable exec.
  */
-#if defined(HAVE_DECL_SECCOMP_SET_MODE_FILTER) && HAVE_DECL_SECCOMP_SET_MODE_FILTER
+#if defined(HAVE_DECL_SECCOMP_MODE_FILTER) && HAVE_DECL_SECCOMP_MODE_FILTER
 
 /* Older systems may not support execveat(2). */
 #ifndef __NR_execveat
@@ -248,4 +248,4 @@ noexec_ctor(void)
     if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == 0)
 	(void)prctl(PR_SET_SECCOMP, SECCOMP_MODE_FILTER, &exec_fprog);
 }
-#endif /* HAVE_DECL_SECCOMP_SET_MODE_FILTER */
+#endif /* HAVE_DECL_SECCOMP_MODE_FILTER */