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calloc: check multiplication overflow

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This commit is contained in:
cinap_lenrek 2012-08-19 10:50:39 +02:00
parent feb58cce49
commit be0301f458
2 changed files with 13 additions and 8 deletions
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14
sys/src/ape/lib/ap/gen/calloc.c
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@ -2,12 +2,14 @@
#include <string.h> #include <string.h>
void * void *
calloc(size_t nmemb, size_t size) calloc(size_t n, size_t s)
{ {
void *mp; void *v;
nmemb = nmemb*size; if(n > 1 && ((size_t)-1)/n < s)
if(mp = malloc(nmemb)) return 0;
memset(mp, 0, nmemb); n *= s;
return(mp); if(v = malloc(n))
memset(v, 0, n);
return v;
} }

7
sys/src/libc/port/malloc.c
View file

@ -280,10 +280,13 @@ msize(void *v)
} }
void* void*
calloc(ulong n, ulong szelem) calloc(ulong n, ulong s)
{ {
void *v; void *v;
if(v = mallocz(n*szelem, 1))
if(n > 1 && ((ulong)-1)/n < s)
return nil;
if(v = mallocz(n*s, 1))
setmalloctag(v, getcallerpc(&n)); setmalloctag(v, getcallerpc(&n));
return v; return v;
} }