Module Name: src
Committed By: rillig
Date: Thu Feb 15 23:48:51 UTC 2024
Modified Files:
src/common/lib/libutil: snprintb.c
src/tests/lib/libutil: t_snprintb.c
Log Message:
snprintb: fix string termination (since today)
In the previous commit, I had accidentally only run the tests for
snprintb_m but not those for snprintb, thereby missing a newly
introduced bug that would not null-terminate the resulting strings.
Add more tests to cover similar situations in which the buffer is too
small to contain the complete output.
To generate a diff of this commit:
cvs rdiff -u -r1.24 -r1.25 src/common/lib/libutil/snprintb.c
cvs rdiff -u -r1.14 -r1.15 src/tests/lib/libutil/t_snprintb.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/common/lib/libutil/snprintb.c
diff -u src/common/lib/libutil/snprintb.c:1.24 src/common/lib/libutil/snprintb.c:1.25
--- src/common/lib/libutil/snprintb.c:1.24 Thu Feb 15 22:48:58 2024
+++ src/common/lib/libutil/snprintb.c Thu Feb 15 23:48:51 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: snprintb.c,v 1.24 2024/02/15 22:48:58 rillig Exp $ */
+/* $NetBSD: snprintb.c,v 1.25 2024/02/15 23:48:51 rillig Exp $ */
/*-
* Copyright (c) 2002 The NetBSD Foundation, Inc.
@@ -41,7 +41,7 @@
# include <sys/cdefs.h>
# if defined(LIBC_SCCS) && !defined(lint)
-__RCSID("$NetBSD: snprintb.c,v 1.24 2024/02/15 22:48:58 rillig Exp $");
+__RCSID("$NetBSD: snprintb.c,v 1.25 2024/02/15 23:48:51 rillig Exp $");
# endif
# include <sys/types.h>
@@ -51,7 +51,7 @@ __RCSID("$NetBSD: snprintb.c,v 1.24 2024
# include <errno.h>
# else /* ! _KERNEL */
# include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: snprintb.c,v 1.24 2024/02/15 22:48:58 rillig Exp $");
+__KERNEL_RCSID(0, "$NetBSD: snprintb.c,v 1.25 2024/02/15 23:48:51 rillig Exp $");
# include <sys/param.h>
# include <sys/inttypes.h>
# include <sys/systm.h>
@@ -275,13 +275,16 @@ snprintb_m(char *buf, size_t bufsize, co
if (sep != '<')
STORE('>');
terminate:
- STORE('\0');
- if (l_max != 0) {
+ if (l_max > 0) {
+ bufsize++;
STORE('\0');
- t_len--;
- buf[bufsize] = '\0';
+ if ((size_t)t_len >= bufsize && bufsize > 1)
+ buf[bufsize - 2] = '\0';
}
- return t_len;
+ STORE('\0');
+ if ((size_t)t_len >= bufsize && bufsize > 0)
+ buf[bufsize - 1] = '\0';
+ return t_len - 1;
internal:
#ifndef _KERNEL
errno = EINVAL;
Index: src/tests/lib/libutil/t_snprintb.c
diff -u src/tests/lib/libutil/t_snprintb.c:1.14 src/tests/lib/libutil/t_snprintb.c:1.15
--- src/tests/lib/libutil/t_snprintb.c:1.14 Thu Feb 15 22:37:10 2024
+++ src/tests/lib/libutil/t_snprintb.c Thu Feb 15 23:48:51 2024
@@ -1,4 +1,4 @@
-/* $NetBSD: t_snprintb.c,v 1.14 2024/02/15 22:37:10 rillig Exp $ */
+/* $NetBSD: t_snprintb.c,v 1.15 2024/02/15 23:48:51 rillig Exp $ */
/*
* Copyright (c) 2002, 2004, 2008, 2010, 2024 The NetBSD Foundation, Inc.
@@ -32,7 +32,7 @@
#include <sys/cdefs.h>
__COPYRIGHT("@(#) Copyright (c) 2008, 2010\
The NetBSD Foundation, inc. All rights reserved.");
-__RCSID("$NetBSD: t_snprintb.c,v 1.14 2024/02/15 22:37:10 rillig Exp $");
+__RCSID("$NetBSD: t_snprintb.c,v 1.15 2024/02/15 23:48:51 rillig Exp $");
#include <stdio.h>
#include <string.h>
@@ -42,19 +42,37 @@ __RCSID("$NetBSD: t_snprintb.c,v 1.14 20
#include <atf-c.h>
static const char *
-vis_arr(const char *arr, size_t arrlen)
+vis_arr(const char *arr, size_t arrsize)
{
static char buf[6][1024];
static size_t i;
i = (i + 1) % (sizeof(buf) / sizeof(buf[0]));
- int rv = strnvisx(buf[i], sizeof(buf[i]), arr, arrlen,
+ int rv = strnvisx(buf[i], sizeof(buf[i]), arr, arrsize,
VIS_WHITE | VIS_OCTAL);
- ATF_REQUIRE_MSG(rv >= 0, "strnvisx failed for length %zu", arrlen);
+ ATF_REQUIRE_MSG(rv >= 0, "strnvisx failed for size %zu", arrsize);
return buf[i];
}
static void
+check_unmodified_loc(const char *file, size_t line,
+ const char *arr, size_t begin, size_t end)
+{
+ size_t mod_begin = begin, mod_end = end;
+ while (mod_begin < mod_end && arr[mod_begin] == 'Z')
+ mod_begin++;
+ while (mod_begin < mod_end && arr[mod_end - 1] == 'Z')
+ mod_end--;
+ ATF_CHECK_MSG(
+ mod_begin == mod_end,
+ "failed:\n"
+ "\ttest case: %s:%zu\n"
+ "\tout-of-bounds write from %zu to %zu: %s\n",
+ file, line,
+ mod_begin, mod_end, vis_arr(arr + mod_begin, mod_end - mod_begin));
+}
+
+static void
h_snprintb_loc(const char *file, size_t line,
size_t bufsize, const char *fmt, size_t fmtlen, uint64_t val,
int exp_rv, const char *res, size_t reslen)
@@ -65,6 +83,7 @@ h_snprintb_loc(const char *file, size_t
// behavior due to out-of-range 'bp'.
ATF_REQUIRE(bufsize > 0);
ATF_REQUIRE(bufsize <= sizeof(buf));
+ ATF_REQUIRE(reslen <= sizeof(buf));
memset(buf, 'Z', sizeof(buf));
int rv = snprintb(buf, bufsize, fmt, val);
@@ -85,6 +104,7 @@ h_snprintb_loc(const char *file, size_t
(uintmax_t)val,
exp_rv, vis_arr(res, reslen),
rv, vis_arr(buf, reslen));
+ check_unmodified_loc(file, line, buf, reslen + 1, sizeof(buf));
}
#define h_snprintb_len(bufsize, fmt, val, exp_rv, res) \
@@ -569,6 +589,52 @@ ATF_TC_BODY(snprintb, tc)
ch,
expected);
}
+
+ // new-style format, small buffer
+#if 0
+ // FIXME: Calling snprintb with buffer size 0 invokes undefined
+ // behavior due to out-of-bounds 'bp' pointer.
+ h_snprintb_len(
+ 0, "\177\020", 0,
+ 1, "ZZZ");
+#endif
+ h_snprintb_len(
+ 1, "\177\020", 0,
+ 1, "\0ZZZ");
+ h_snprintb_len(
+ 2, "\177\020", 0,
+ 1, "0\0ZZZ");
+ h_snprintb_len(
+ 3, "\177\020", 0,
+ 1, "0\0ZZZ");
+ h_snprintb_len(
+ 3, "\177\020", 7,
+ 3, "0x\0ZZZ");
+ h_snprintb_len(
+ 4, "\177\020", 7,
+ 3, "0x7\0ZZZ");
+ h_snprintb_len(
+ 7, "\177\020b\000lsb\0", 7,
+ 8, "0x7<ls\0ZZZ");
+ h_snprintb_len(
+ 8, "\177\020b\000lsb\0", 7,
+ 8, "0x7<lsb\0ZZZ");
+ h_snprintb_len(
+ 9, "\177\020b\000lsb\0", 7,
+ 8, "0x7<lsb>\0ZZZ");
+ h_snprintb_len(
+ 9, "\177\020b\000one\0b\001two\0", 7,
+ 12, "0x7<one,\0ZZZ");
+ h_snprintb_len(
+ 10, "\177\020b\000one\0b\001two\0", 7,
+ 12, "0x7<one,t\0ZZZ");
+ h_snprintb_len(
+ 12, "\177\020b\000one\0b\001two\0", 7,
+ 12, "0x7<one,two\0ZZZ");
+ h_snprintb_len(
+ 13, "\177\020b\000one\0b\001two\0", 7,
+ 12, "0x7<one,two>\0ZZZ");
+
}
static void
@@ -580,6 +646,7 @@ h_snprintb_m_loc(const char *file, size_
ATF_REQUIRE(bufsize > 1);
ATF_REQUIRE(bufsize <= sizeof(buf));
+ ATF_REQUIRE(reslen <= sizeof(buf));
memset(buf, 'Z', sizeof(buf));
int rv = snprintb_m(buf, bufsize, fmt, val, max);
@@ -603,6 +670,7 @@ h_snprintb_m_loc(const char *file, size_
max,
exp_rv, vis_arr(res, reslen),
total, vis_arr(buf, reslen));
+ check_unmodified_loc(file, line, buf, reslen + 1, sizeof(buf));
}
#define h_snprintb_m_len(bufsize, fmt, val, line_max, exp_rv, res) \
@@ -675,6 +743,17 @@ ATF_TC_BODY(snprintb_m, tc)
/* 140 */ "ZZZZZZZZZZ"
);
+ // new-style format, buffer too small for description
+ h_snprintb_m_len(
+ 8,
+ "\177\020"
+ "b\000bit1\0",
+ 0x0001,
+ 64,
+ 10,
+ "0x1<bi\0\0ZZZ"
+ );
+
h_snprintb_m(
"\177\020"
"b\0LSB\0"
