From: gnezdo <gnezdo@openbsd.org>
Date: Sat, 12 Aug 2023 13:43:22 +0000 (+0000)
Subject: Check for a full read, avoid warn when errno might be unmodified
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=d4a5aacda412f32f85bea992823bf81bf9364c8e;p=openbsd

Check for a full read, avoid warn when errno might be unmodified

Promote size from int to size_t.

From: lucas at sexy dot is

Regress tests by gnezdo@

deraadt: yes
---

diff --git a/libexec/ld.so/ldd/ldd.c b/libexec/ld.so/ldd/ldd.c
index 9e8c5065cd8..f8f208652d2 100644
--- a/libexec/ld.so/ldd/ldd.c
+++ b/libexec/ld.so/ldd/ldd.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: ldd.c,v 1.24 2023/07/24 01:02:47 deraadt Exp $	*/
+/*	$OpenBSD: ldd.c,v 1.25 2023/08/12 13:43:22 gnezdo Exp $	*/
 /*
  * Copyright (c) 2001 Artur Grabowski <art@openbsd.org>
  * All rights reserved.
@@ -96,7 +96,8 @@ doit(char *name)
 {
 	Elf_Ehdr ehdr;
 	Elf_Phdr *phdr;
-	int fd, i, size, status, interp=0;
+	size_t size;
+	int fd, i, status, interp=0;
 	char buf[PATH_MAX];
 	struct stat st;
 	void * dlhandle;
@@ -118,8 +119,8 @@ doit(char *name)
 		return 1;
 	}
 
-	if (read(fd, &ehdr, sizeof(ehdr)) < 0) {
-		warn("read(%s)", name);
+	if (read(fd, &ehdr, sizeof(ehdr)) != sizeof(ehdr)) {
+		warnx("%s: incomplete ELF header", name);
 		close(fd);
 		return 1;
 	}
@@ -141,7 +142,7 @@ doit(char *name)
 	size = ehdr.e_phnum * sizeof(Elf_Phdr);
 
 	if (pread(fd, phdr, size, ehdr.e_phoff) != size) {
-		warn("read(%s)", name);
+		warnx("%s: incomplete program header", name);
 		close(fd);
 		free(phdr);
 		return 1;
diff --git a/regress/libexec/ld.so/Makefile b/regress/libexec/ld.so/Makefile
index e4c908ddaaf..5b746bb347c 100644
--- a/regress/libexec/ld.so/Makefile
+++ b/regress/libexec/ld.so/Makefile
@@ -1,10 +1,10 @@
-#	$OpenBSD: Makefile,v 1.19 2022/08/20 14:13:48 sthen Exp $
+#	$OpenBSD: Makefile,v 1.20 2023/08/12 13:43:22 gnezdo Exp $
 
 SUBDIR+= elf hidden weak dlsym dlopen dlclose lazy
 SUBDIR+= constructor 
 SUBDIR+= link-order edgecases initfirst
 SUBDIR+= df_1_noopen randomdata subst dependencies
-SUBDIR+= init-env nodelete noload
+SUBDIR+= init-env nodelete noload ldd
 
 install:
 
diff --git a/regress/libexec/ld.so/ldd/Makefile b/regress/libexec/ld.so/ldd/Makefile
new file mode 100644
index 00000000000..b8b79d64d86
--- /dev/null
+++ b/regress/libexec/ld.so/ldd/Makefile
@@ -0,0 +1,19 @@
+# $OpenBSD: Makefile,v 1.1 2023/08/12 13:43:22 gnezdo Exp $
+
+.include <bsd.own.mk>
+
+REGRESS_TARGETS = test
+
+.include <bsd.regress.mk>
+
+CLEANFILES+=empty short
+
+.PHONY: test
+test: empty short
+	${SHELL} ${.CURDIR}/test.sh
+
+empty:
+	touch empty
+
+short:
+	dd if=/usr/bin/ldd of=short count=128 bs=1
diff --git a/regress/libexec/ld.so/ldd/test.sh b/regress/libexec/ld.so/ldd/test.sh
new file mode 100755
index 00000000000..2e5ce70cfff
--- /dev/null
+++ b/regress/libexec/ld.so/ldd/test.sh
@@ -0,0 +1,18 @@
+#!/bin/sh -ex
+# $OpenBSD: test.sh,v 1.1 2023/08/12 13:43:22 gnezdo Exp $
+
+res=0
+
+test() {
+  if eval "$@"; then
+    echo "passed"
+  else
+    echo "FAILED"
+    res=1
+  fi
+}
+
+test "ldd empty 2>&1 | grep 'incomplete ELF header'"
+test "ldd short 2>&1 | grep 'incomplete program header'"
+
+exit $res