Revision 447ac906e189535e77dcb1f4bbe3f1bc917d4c12 authored by Patrick Steinhardt on 01 December 2022, 14:45:31 UTC, committed by Junio C Hamano on 05 December 2022, 06:14:16 UTC
The `struct attr_stack` tracks the stack of all patterns together with their attributes. When parsing a gitattributes file that has more than 2^31 such patterns though we may trigger multiple out-of-bounds reads on 64 bit platforms. This is because while the `num_matches` variable is an unsigned integer, we always use a signed integer to iterate over them. I have not been able to reproduce this issue due to memory constraints on my systems. But despite the out-of-bounds reads, the worst thing that can seemingly happen is to call free(3P) with a garbage pointer when calling `attr_stack_free()`. Fix this bug by using unsigned integers to iterate over the array. While this makes the iteration somewhat awkward when iterating in reverse, it is at least better than knowingly running into an out-of-bounds read. While at it, convert the call to `ALLOC_GROW` to use `ALLOC_GROW_BY` instead. Signed-off-by: Patrick Steinhardt <ps@pks.im> Signed-off-by: Junio C Hamano <gitster@pobox.com>
1 parent 34ace8b
sideband.c
#include "cache.h"
#include "color.h"
#include "config.h"
#include "sideband.h"
#include "help.h"
#include "pkt-line.h"
struct keyword_entry {
/*
* We use keyword as config key so it should be a single alphanumeric word.
*/
const char *keyword;
char color[COLOR_MAXLEN];
};
static struct keyword_entry keywords[] = {
{ "hint", GIT_COLOR_YELLOW },
{ "warning", GIT_COLOR_BOLD_YELLOW },
{ "success", GIT_COLOR_BOLD_GREEN },
{ "error", GIT_COLOR_BOLD_RED },
};
/* Returns a color setting (GIT_COLOR_NEVER, etc). */
static int use_sideband_colors(void)
{
static int use_sideband_colors_cached = -1;
const char *key = "color.remote";
struct strbuf sb = STRBUF_INIT;
char *value;
int i;
if (use_sideband_colors_cached >= 0)
return use_sideband_colors_cached;
if (!git_config_get_string(key, &value)) {
use_sideband_colors_cached = git_config_colorbool(key, value);
} else if (!git_config_get_string("color.ui", &value)) {
use_sideband_colors_cached = git_config_colorbool("color.ui", value);
} else {
use_sideband_colors_cached = GIT_COLOR_AUTO;
}
for (i = 0; i < ARRAY_SIZE(keywords); i++) {
strbuf_reset(&sb);
strbuf_addf(&sb, "%s.%s", key, keywords[i].keyword);
if (git_config_get_string(sb.buf, &value))
continue;
if (color_parse(value, keywords[i].color))
continue;
}
strbuf_release(&sb);
return use_sideband_colors_cached;
}
void list_config_color_sideband_slots(struct string_list *list, const char *prefix)
{
int i;
for (i = 0; i < ARRAY_SIZE(keywords); i++)
list_config_item(list, prefix, keywords[i].keyword);
}
/*
* Optionally highlight one keyword in remote output if it appears at the start
* of the line. This should be called for a single line only, which is
* passed as the first N characters of the SRC array.
*
* NEEDSWORK: use "size_t n" instead for clarity.
*/
static void maybe_colorize_sideband(struct strbuf *dest, const char *src, int n)
{
int i;
if (!want_color_stderr(use_sideband_colors())) {
strbuf_add(dest, src, n);
return;
}
while (0 < n && isspace(*src)) {
strbuf_addch(dest, *src);
src++;
n--;
}
for (i = 0; i < ARRAY_SIZE(keywords); i++) {
struct keyword_entry *p = keywords + i;
int len = strlen(p->keyword);
if (n < len)
continue;
/*
* Match case insensitively, so we colorize output from existing
* servers regardless of the case that they use for their
* messages. We only highlight the word precisely, so
* "successful" stays uncolored.
*/
if (!strncasecmp(p->keyword, src, len) &&
(len == n || !isalnum(src[len]))) {
strbuf_addstr(dest, p->color);
strbuf_add(dest, src, len);
strbuf_addstr(dest, GIT_COLOR_RESET);
n -= len;
src += len;
break;
}
}
strbuf_add(dest, src, n);
}
#define DISPLAY_PREFIX "remote: "
#define ANSI_SUFFIX "\033[K"
#define DUMB_SUFFIX " "
int demultiplex_sideband(const char *me, int status,
char *buf, int len,
int die_on_error,
struct strbuf *scratch,
enum sideband_type *sideband_type)
{
static const char *suffix;
const char *b, *brk;
int band;
if (!suffix) {
if (isatty(2) && !is_terminal_dumb())
suffix = ANSI_SUFFIX;
else
suffix = DUMB_SUFFIX;
}
if (status == PACKET_READ_EOF) {
strbuf_addf(scratch,
"%s%s: unexpected disconnect while reading sideband packet",
scratch->len ? "\n" : "", me);
*sideband_type = SIDEBAND_PROTOCOL_ERROR;
goto cleanup;
}
if (len < 0)
BUG("negative length on non-eof packet read");
if (len == 0) {
if (status == PACKET_READ_NORMAL) {
strbuf_addf(scratch,
"%s%s: protocol error: missing sideband designator",
scratch->len ? "\n" : "", me);
*sideband_type = SIDEBAND_PROTOCOL_ERROR;
} else {
/* covers flush, delim, etc */
*sideband_type = SIDEBAND_FLUSH;
}
goto cleanup;
}
band = buf[0] & 0xff;
buf[len] = '\0';
len--;
switch (band) {
case 3:
if (die_on_error)
die(_("remote error: %s"), buf + 1);
strbuf_addf(scratch, "%s%s", scratch->len ? "\n" : "",
DISPLAY_PREFIX);
maybe_colorize_sideband(scratch, buf + 1, len);
*sideband_type = SIDEBAND_REMOTE_ERROR;
break;
case 2:
b = buf + 1;
/*
* Append a suffix to each nonempty line to clear the
* end of the screen line.
*
* The output is accumulated in a buffer and
* each line is printed to stderr using
* write(2) to ensure inter-process atomicity.
*/
while ((brk = strpbrk(b, "\n\r"))) {
int linelen = brk - b;
if (!scratch->len)
strbuf_addstr(scratch, DISPLAY_PREFIX);
if (linelen > 0) {
maybe_colorize_sideband(scratch, b, linelen);
strbuf_addstr(scratch, suffix);
}
strbuf_addch(scratch, *brk);
xwrite(2, scratch->buf, scratch->len);
strbuf_reset(scratch);
b = brk + 1;
}
if (*b) {
strbuf_addstr(scratch, scratch->len ?
"" : DISPLAY_PREFIX);
maybe_colorize_sideband(scratch, b, strlen(b));
}
return 0;
case 1:
*sideband_type = SIDEBAND_PRIMARY;
return 1;
default:
strbuf_addf(scratch, "%s%s: protocol error: bad band #%d",
scratch->len ? "\n" : "", me, band);
*sideband_type = SIDEBAND_PROTOCOL_ERROR;
break;
}
cleanup:
if (die_on_error && *sideband_type == SIDEBAND_PROTOCOL_ERROR)
die("%s", scratch->buf);
if (scratch->len) {
strbuf_addch(scratch, '\n');
xwrite(2, scratch->buf, scratch->len);
}
strbuf_release(scratch);
return 1;
}
/*
* fd is connected to the remote side; send the sideband data
* over multiplexed packet stream.
*/
void send_sideband(int fd, int band, const char *data, ssize_t sz, int packet_max)
{
const char *p = data;
while (sz) {
unsigned n;
char hdr[5];
n = sz;
if (packet_max - 5 < n)
n = packet_max - 5;
if (0 <= band) {
xsnprintf(hdr, sizeof(hdr), "%04x", n + 5);
hdr[4] = band;
write_or_die(fd, hdr, 5);
} else {
xsnprintf(hdr, sizeof(hdr), "%04x", n + 4);
write_or_die(fd, hdr, 4);
}
write_or_die(fd, p, n);
p += n;
sz -= n;
}
}
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