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
versioncmp.c
#include "cache.h"
#include "config.h"
#include "string-list.h"
/*
* versioncmp(): copied from string/strverscmp.c in glibc commit
* ee9247c38a8def24a59eb5cfb7196a98bef8cfdc, reformatted to Git coding
* style. The implementation is under LGPL-2.1 and Git relicenses it
* to GPLv2.
*/
/*
* states: S_N: normal, S_I: comparing integral part, S_F: comparing
* fractionnal parts, S_Z: idem but with leading Zeroes only
*/
#define S_N 0x0
#define S_I 0x3
#define S_F 0x6
#define S_Z 0x9
/* result_type: CMP: return diff; LEN: compare using len_diff/diff */
#define CMP 2
#define LEN 3
static const struct string_list *prereleases;
static int initialized;
struct suffix_match {
int conf_pos;
int start;
int len;
};
static void find_better_matching_suffix(const char *tagname, const char *suffix,
int suffix_len, int start, int conf_pos,
struct suffix_match *match)
{
/*
* A better match either starts earlier or starts at the same offset
* but is longer.
*/
int end = match->len < suffix_len ? match->start : match->start-1;
int i;
for (i = start; i <= end; i++)
if (starts_with(tagname + i, suffix)) {
match->conf_pos = conf_pos;
match->start = i;
match->len = suffix_len;
break;
}
}
/*
* off is the offset of the first different character in the two strings
* s1 and s2. If either s1 or s2 contains a prerelease suffix containing
* that offset or a suffix ends right before that offset, then that
* string will be forced to be on top.
*
* If both s1 and s2 contain a (different) suffix around that position,
* their order is determined by the order of those two suffixes in the
* configuration.
* If any of the strings contains more than one different suffixes around
* that position, then that string is sorted according to the contained
* suffix which starts at the earliest offset in that string.
* If more than one different contained suffixes start at that earliest
* offset, then that string is sorted according to the longest of those
* suffixes.
*
* Return non-zero if *diff contains the return value for versioncmp()
*/
static int swap_prereleases(const char *s1,
const char *s2,
int off,
int *diff)
{
int i;
struct suffix_match match1 = { -1, off, -1 };
struct suffix_match match2 = { -1, off, -1 };
for (i = 0; i < prereleases->nr; i++) {
const char *suffix = prereleases->items[i].string;
int start, suffix_len = strlen(suffix);
if (suffix_len < off)
start = off - suffix_len;
else
start = 0;
find_better_matching_suffix(s1, suffix, suffix_len, start,
i, &match1);
find_better_matching_suffix(s2, suffix, suffix_len, start,
i, &match2);
}
if (match1.conf_pos == -1 && match2.conf_pos == -1)
return 0;
if (match1.conf_pos == match2.conf_pos)
/* Found the same suffix in both, e.g. "-rc" in "v1.0-rcX"
* and "v1.0-rcY": the caller should decide based on "X"
* and "Y". */
return 0;
if (match1.conf_pos >= 0 && match2.conf_pos >= 0)
*diff = match1.conf_pos - match2.conf_pos;
else if (match1.conf_pos >= 0)
*diff = -1;
else /* if (match2.conf_pos >= 0) */
*diff = 1;
return 1;
}
/*
* Compare S1 and S2 as strings holding indices/version numbers,
* returning less than, equal to or greater than zero if S1 is less
* than, equal to or greater than S2 (for more info, see the texinfo
* doc).
*/
int versioncmp(const char *s1, const char *s2)
{
const unsigned char *p1 = (const unsigned char *) s1;
const unsigned char *p2 = (const unsigned char *) s2;
unsigned char c1, c2;
int state, diff;
/*
* Symbol(s) 0 [1-9] others
* Transition (10) 0 (01) d (00) x
*/
static const uint8_t next_state[] = {
/* state x d 0 */
/* S_N */ S_N, S_I, S_Z,
/* S_I */ S_N, S_I, S_I,
/* S_F */ S_N, S_F, S_F,
/* S_Z */ S_N, S_F, S_Z
};
static const int8_t result_type[] = {
/* state x/x x/d x/0 d/x d/d d/0 0/x 0/d 0/0 */
/* S_N */ CMP, CMP, CMP, CMP, LEN, CMP, CMP, CMP, CMP,
/* S_I */ CMP, -1, -1, +1, LEN, LEN, +1, LEN, LEN,
/* S_F */ CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP, CMP,
/* S_Z */ CMP, +1, +1, -1, CMP, CMP, -1, CMP, CMP
};
if (p1 == p2)
return 0;
c1 = *p1++;
c2 = *p2++;
/* Hint: '0' is a digit too. */
state = S_N + ((c1 == '0') + (isdigit (c1) != 0));
while ((diff = c1 - c2) == 0) {
if (c1 == '\0')
return diff;
state = next_state[state];
c1 = *p1++;
c2 = *p2++;
state += (c1 == '0') + (isdigit (c1) != 0);
}
if (!initialized) {
const struct string_list *deprecated_prereleases;
initialized = 1;
prereleases = git_config_get_value_multi("versionsort.suffix");
deprecated_prereleases = git_config_get_value_multi("versionsort.prereleasesuffix");
if (prereleases) {
if (deprecated_prereleases)
warning("ignoring versionsort.prereleasesuffix because versionsort.suffix is set");
} else
prereleases = deprecated_prereleases;
}
if (prereleases && swap_prereleases(s1, s2, (const char *) p1 - s1 - 1,
&diff))
return diff;
state = result_type[state * 3 + (((c2 == '0') + (isdigit (c2) != 0)))];
switch (state) {
case CMP:
return diff;
case LEN:
while (isdigit (*p1++))
if (!isdigit (*p2++))
return 1;
return isdigit (*p2) ? -1 : diff;
default:
return state;
}
}
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