[git commit] Replace int -> uint to avoid signed integer overflow

Denys Vlasenko vda.linux at googlemail.com
Sat Feb 4 22:10:22 UTC 2017


commit: https://git.busybox.net/busybox/commit/?id=8762512fdb088acefb9f3ea5f7b1e1bf2d336ff3
branch: https://git.busybox.net/busybox/commit/?id=refs/heads/master

An example of such an error (should be compiled with DEBUG_SANITIZE):

runtime error: left shift of 1 by 31 places cannot be represented in
type 'int'

Signed-off-by: Rostislav Skudnov <rostislav at tuxera.com>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
---
 archival/libarchive/decompress_bunzip2.c | 6 +++---
 libbb/crc32.c                            | 2 +-
 libbb/getopt32.c                         | 4 ++--
 libbb/pw_encrypt.c                       | 2 +-
 miscutils/rx.c                           | 2 +-
 5 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/archival/libarchive/decompress_bunzip2.c b/archival/libarchive/decompress_bunzip2.c
index fe5953d..4fb989c 100644
--- a/archival/libarchive/decompress_bunzip2.c
+++ b/archival/libarchive/decompress_bunzip2.c
@@ -134,7 +134,7 @@ static unsigned get_bits(bunzip_data *bd, int bits_wanted)
 
 		/* Avoid 32-bit overflow (dump bit buffer to top of output) */
 		if (bit_count >= 24) {
-			bits = bd->inbufBits & ((1 << bit_count) - 1);
+			bits = bd->inbufBits & ((1U << bit_count) - 1);
 			bits_wanted -= bit_count;
 			bits <<= bits_wanted;
 			bit_count = 0;
@@ -158,11 +158,11 @@ static int get_next_block(bunzip_data *bd)
 {
 	struct group_data *hufGroup;
 	int dbufCount, dbufSize, groupCount, *base, *limit, selector,
-		i, j, t, runPos, symCount, symTotal, nSelectors, byteCount[256];
+		i, j, runPos, symCount, symTotal, nSelectors, byteCount[256];
 	int runCnt = runCnt; /* for compiler */
 	uint8_t uc, symToByte[256], mtfSymbol[256], *selectors;
 	uint32_t *dbuf;
-	unsigned origPtr;
+	unsigned origPtr, t;
 
 	dbuf = bd->dbuf;
 	dbufSize = bd->dbufSize;
diff --git a/libbb/crc32.c b/libbb/crc32.c
index ac9836c..0711ca8 100644
--- a/libbb/crc32.c
+++ b/libbb/crc32.c
@@ -24,7 +24,7 @@ uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian)
 {
 	uint32_t polynomial = endian ? 0x04c11db7 : 0xedb88320;
 	uint32_t c;
-	int i, j;
+	unsigned i, j;
 
 	if (!crc_table)
 		crc_table = xmalloc(256 * sizeof(uint32_t));
diff --git a/libbb/getopt32.c b/libbb/getopt32.c
index 15b6efc..497fc01 100644
--- a/libbb/getopt32.c
+++ b/libbb/getopt32.c
@@ -404,7 +404,7 @@ getopt32(char **argv, const char *applet_opts, ...)
 		if (c >= 32)
 			break;
 		on_off->opt_char = *s;
-		on_off->switch_on = (1 << c);
+		on_off->switch_on = (1U << c);
 		if (*++s == ':') {
 			on_off->optarg = va_arg(p, void **);
 			if (s[1] == '+' || s[1] == '*') {
@@ -454,7 +454,7 @@ getopt32(char **argv, const char *applet_opts, ...)
 			if (c >= 32)
 				break;
 			on_off->opt_char = l_o->val;
-			on_off->switch_on = (1 << c);
+			on_off->switch_on = (1U << c);
 			if (l_o->has_arg != no_argument)
 				on_off->optarg = va_arg(p, void **);
 			c++;
diff --git a/libbb/pw_encrypt.c b/libbb/pw_encrypt.c
index 4cdc2de..fe06a8f 100644
--- a/libbb/pw_encrypt.c
+++ b/libbb/pw_encrypt.c
@@ -30,7 +30,7 @@ static int i64c(int i)
 int FAST_FUNC crypt_make_salt(char *p, int cnt /*, int x */)
 {
 	/* was: x += ... */
-	int x = getpid() + monotonic_us();
+	unsigned x = getpid() + monotonic_us();
 	do {
 		/* x = (x*1664525 + 1013904223) % 2^32 generator is lame
 		 * (low-order bit is not "random", etc...),
diff --git a/miscutils/rx.c b/miscutils/rx.c
index 36fc20a..1f6f282 100644
--- a/miscutils/rx.c
+++ b/miscutils/rx.c
@@ -94,7 +94,7 @@ static int receive(/*int read_fd, */int file_fd)
 		int blockBegin;
 		int blockNo, blockNoOnesCompl;
 		int cksum_or_crc;
-		int expected;
+		unsigned expected;
 		int i, j;
 
 		blockBegin = read_byte(timeout);


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