tal: tal_dup()

[ccan] / ccan / tal / tal.c

diff --git a/ccan/tal/tal.c b/ccan/tal/tal.c
index ffe2d71334dce4473d57243bca0827aaa5fee565..88bcb5ab6135257529eda0e999df024507c0386d 100644 (file)
--- a/ccan/tal/tal.c
+++ b/ccan/tal/tal.c
@@ -665,6 +665,12 @@ bool tal_resize_(tal_t **ctxp, size_t size)
 
         old_t = debug_tal(to_tal_hdr(*ctxp));
 
+       /* Don't hand silly sizes to realloc. */
+       if (size >> (CHAR_BIT*sizeof(size) - 1)) {
+               call_error("Reallocation size overflow");
+               return false;
+       }
+
         t = resizefn(old_t, size + sizeof(struct tal_hdr));
        if (!t) {
                call_error("Reallocation failure");
@@ -699,7 +705,7 @@ bool tal_resize_(tal_t **ctxp, size_t size)
 
 char *tal_strdup(const tal_t *ctx, const char *p)
 {
-       return tal_memdup(ctx, p, strlen(p)+1);
+       return tal_dup(ctx, char, p, strlen(p)+1, 0);
 }
 
 char *tal_strndup(const tal_t *ctx, const char *p, size_t n)
@@ -708,20 +714,35 @@ char *tal_strndup(const tal_t *ctx, const char *p, size_t n)
 
        if (strlen(p) < n)
                n = strlen(p);
-       ret = tal_memdup(ctx, p, n+1);
+       ret = tal_dup(ctx, char, p, n, 1);
        if (ret)
                ret[n] = '\0';
        return ret;
 }
 
-void *tal_memdup(const tal_t *ctx, const void *p, size_t n)
+void *tal_dup_(const tal_t *ctx, const void *p, size_t n, size_t extra,
+              const char *label)
 {
        void *ret;
 
-       if (ctx == TAL_TAKE)
-               return (void *)p;
+       /* Beware overflow! */
+       if (n + extra < n || n + extra + sizeof(struct tal_hdr) < n) {
+               call_error("dup size overflow");
+               if (ctx == TAL_TAKE)
+                       tal_free(p);
+               return NULL;
+       }
 
-       ret = tal_arr(ctx, char, n);
+       if (ctx == TAL_TAKE) {
+               if (unlikely(!p))
+                       return NULL;
+               if (!tal_resize_((void **)&p, n + extra)) {
+                       tal_free(p);
+                       return NULL;
+               }
+               return (void *)p;
+       }
+       ret = tal_alloc_(ctx, n + extra, false, label);
        if (ret)
                memcpy(ret, p, n);
        return ret;