patch 9.1.0089: qsort() comparison functions should be transitive
Problem: qsort() comparison functions should be transitive
Solution: Do not subtract values, but rather use explicit comparisons
Improve qsort() comparison functions
There has been a recent report on qsort() causing out-of-bounds read &
write in glibc for non transitive comparison functions
https://www.qualys.com/2024/01/30/qsort.txt
Even so the bug is in glibc's implementation of the qsort() algorithm,
it's bad style to just use substraction for the comparison functions,
which may cause overflow issues and as hinted at in OpenBSD's manual
page for qsort(): "It is almost always an error to use subtraction to
compute the return value of the comparison function."
So check the qsort() comparison functions and change them to be safe.
closes: #13980
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/ex_cmds.c b/src/ex_cmds.c
index e7f689b..720e918 100644
--- a/src/ex_cmds.c
+++ b/src/ex_cmds.c
@@ -323,7 +323,7 @@
if (sort_nr)
{
if (l1.st_u.num.is_number != l2.st_u.num.is_number)
- result = l1.st_u.num.is_number - l2.st_u.num.is_number;
+ result = l1.st_u.num.is_number > l2.st_u.num.is_number ? 1 : -1;
else
result = l1.st_u.num.value == l2.st_u.num.value ? 0
: l1.st_u.num.value > l2.st_u.num.value ? 1 : -1;
diff --git a/src/mbyte.c b/src/mbyte.c
index ee2834c..2d18a27 100644
--- a/src/mbyte.c
+++ b/src/mbyte.c
@@ -5613,7 +5613,8 @@
listitem_T *li1 = *(listitem_T **)a1;
listitem_T *li2 = *(listitem_T **)a2;
- return li1->li_tv.vval.v_number - li2->li_tv.vval.v_number;
+ return li1->li_tv.vval.v_number == li2->li_tv.vval.v_number ? 0 :
+ li1->li_tv.vval.v_number > li2->li_tv.vval.v_number ? 1 : -1;
}
void
diff --git a/src/profiler.c b/src/profiler.c
index 780b958..504d713 100644
--- a/src/profiler.c
+++ b/src/profiler.c
@@ -287,11 +287,13 @@
profile_cmp(const proftime_T *tm1, const proftime_T *tm2)
{
# ifdef MSWIN
- return (int)(tm2->QuadPart - tm1->QuadPart);
+ return tm2->QuadPart == tm1->QuadPart ? 0 :
+ tm2->QuadPart > tm1->QuadPart ? 1 : -1;
# else
if (tm1->tv_sec == tm2->tv_sec)
- return tm2->tv_fsec - tm1->tv_fsec;
- return tm2->tv_sec - tm1->tv_sec;
+ return tm2->tv_fsec == tm1->tv_fsec ? 0 :
+ tm2->tv_fsec > tm1->tv_fsec ? 1 : -1;
+ return tm2->tv_sec > tm1->tv_sec ? 1 : -1;
# endif
}
diff --git a/src/search.c b/src/search.c
index d4baa91..eadbcd3 100644
--- a/src/search.c
+++ b/src/search.c
@@ -4908,7 +4908,10 @@
int idx1 = ((fuzmatch_str_T *)s1)->idx;
int idx2 = ((fuzmatch_str_T *)s2)->idx;
- return v1 == v2 ? (idx1 - idx2) : v1 > v2 ? -1 : 1;
+ if (v1 == v2)
+ return idx1 == idx2 ? 0 : idx1 > idx2 ? 1 : -1;
+ else
+ return v1 > v2 ? -1 : 1;
}
/*
@@ -4936,9 +4939,14 @@
char_u *str1 = ((fuzmatch_str_T *)s1)->str;
char_u *str2 = ((fuzmatch_str_T *)s2)->str;
- if (*str1 != '<' && *str2 == '<') return -1;
- if (*str1 == '<' && *str2 != '<') return 1;
- return v1 == v2 ? (idx1 - idx2) : v1 > v2 ? -1 : 1;
+ if (*str1 != '<' && *str2 == '<')
+ return -1;
+ if (*str1 == '<' && *str2 != '<')
+ return 1;
+ if (v1 == v2)
+ return idx1 == idx2 ? 0 : idx1 > idx2 ? 1 : -1;
+ else
+ return v1 > v2 ? -1 : 1;
}
/*
diff --git a/src/spellsuggest.c b/src/spellsuggest.c
index ecc0a74..82499c0 100644
--- a/src/spellsuggest.c
+++ b/src/spellsuggest.c
@@ -3763,11 +3763,16 @@
{
suggest_T *p1 = (suggest_T *)s1;
suggest_T *p2 = (suggest_T *)s2;
- int n = p1->st_score - p2->st_score;
+ int n;
+
+ n = p1->st_score == p2->st_score ? 0 :
+ p1->st_score > p2->st_score ? 1 : -1;
if (n == 0)
{
- n = p1->st_altscore - p2->st_altscore;
+ n = p1->st_altscore == p2->st_altscore ? 0 :
+ p1->st_altscore > p2->st_altscore ? 1 : -1;
+
if (n == 0)
n = STRICMP(p1->st_word, p2->st_word);
}
diff --git a/src/version.c b/src/version.c
index 1332f46..a4132db 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
static int included_patches[] =
{ /* Add new patch number below this line */
/**/
+ 89,
+/**/
88,
/**/
87,
diff --git a/src/window.c b/src/window.c
index 5cb6c3c..a7d9319 100644
--- a/src/window.c
+++ b/src/window.c
@@ -7753,9 +7753,15 @@
* Simple int comparison function for use with qsort()
*/
static int
-int_cmp(const void *a, const void *b)
+int_cmp(const void *pa, const void *pb)
{
- return *(const int *)a - *(const int *)b;
+ const int a = *(const int *)pa;
+ const int b = *(const int *)pb;
+ if (a > b)
+ return 1;
+ if (a < b)
+ return -1;
+ return 0;
}
/*