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git/diffcore-order.c
Antoine Pelisse fc2b621454 Prevent buffer overflows when path is too long
Some buffers created with PATH_MAX length are not checked when being
written, and can overflow if PATH_MAX is not big enough to hold the
path.

Replace those buffers by strbufs so that their size is automatically
grown if necessary. They are created as static local variables to avoid
reallocating memory on each call. Note that prefix_filename() returns
this static buffer so each callers should copy or use the string
immediately (this is currently true).

Reported-by: Wataru Noguchi <wnoguchi.0727@gmail.com>
Signed-off-by: Antoine Pelisse <apelisse@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2013-12-16 14:06:19 -08:00

126 lines
2.2 KiB
C

/*
* Copyright (C) 2005 Junio C Hamano
*/
#include "cache.h"
#include "diff.h"
#include "diffcore.h"
static char **order;
static int order_cnt;
static void prepare_order(const char *orderfile)
{
int fd, cnt, pass;
void *map;
char *cp, *endp;
struct stat st;
size_t sz;
if (order)
return;
fd = open(orderfile, O_RDONLY);
if (fd < 0)
return;
if (fstat(fd, &st)) {
close(fd);
return;
}
sz = xsize_t(st.st_size);
map = mmap(NULL, sz, PROT_READ|PROT_WRITE, MAP_PRIVATE, fd, 0);
close(fd);
if (map == MAP_FAILED)
return;
endp = (char *) map + sz;
for (pass = 0; pass < 2; pass++) {
cnt = 0;
cp = map;
while (cp < endp) {
char *ep;
for (ep = cp; ep < endp && *ep != '\n'; ep++)
;
/* cp to ep has one line */
if (*cp == '\n' || *cp == '#')
; /* comment */
else if (pass == 0)
cnt++;
else {
if (*ep == '\n') {
*ep = 0;
order[cnt] = cp;
} else {
order[cnt] = xmemdupz(cp, ep - cp);
}
cnt++;
}
if (ep < endp)
ep++;
cp = ep;
}
if (pass == 0) {
order_cnt = cnt;
order = xmalloc(sizeof(*order) * cnt);
}
}
}
struct pair_order {
struct diff_filepair *pair;
int orig_order;
int order;
};
static int match_order(const char *path)
{
int i;
static struct strbuf p = STRBUF_INIT;
for (i = 0; i < order_cnt; i++) {
strbuf_reset(&p);
strbuf_addstr(&p, path);
while (p.buf[0]) {
char *cp;
if (!fnmatch(order[i], p.buf, 0))
return i;
cp = strrchr(p.buf, '/');
if (!cp)
break;
*cp = 0;
}
}
return order_cnt;
}
static int compare_pair_order(const void *a_, const void *b_)
{
struct pair_order const *a, *b;
a = (struct pair_order const *)a_;
b = (struct pair_order const *)b_;
if (a->order != b->order)
return a->order - b->order;
return a->orig_order - b->orig_order;
}
void diffcore_order(const char *orderfile)
{
struct diff_queue_struct *q = &diff_queued_diff;
struct pair_order *o;
int i;
if (!q->nr)
return;
o = xmalloc(sizeof(*o) * q->nr);
prepare_order(orderfile);
for (i = 0; i < q->nr; i++) {
o[i].pair = q->queue[i];
o[i].orig_order = i;
o[i].order = match_order(o[i].pair->two->path);
}
qsort(o, q->nr, sizeof(*o), compare_pair_order);
for (i = 0; i < q->nr; i++)
q->queue[i] = o[i].pair;
free(o);
return;
}