Hello All,
In reviewing code in LuaJIT 2.0.x, I found a number of instances where
calls to malloc() were made, but no corresponding test for NULL is done,
which would indicate failure. I know that linux does memory overcommiting,
but the patch file below (in diff -u) format adds the needed checks:
--- buildvm.c.orig 2015-02-21 09:45:46.229623401 -0800
+++ buildvm.c 2015-02-21 09:53:52.214389566 -0800
@@ -120,6 +120,10 @@
#endif
}
p = (char *)malloc(strlen(name)+1); /* MSVC doesn't like strdup. */
+ if (p == NULL) { /* malloc() failed, what do we do now? */
+ /* should we print a warning message? */
+ return NULL;
+ }
strcpy(p, name);
return p;
}
@@ -175,11 +179,20 @@
/* Initialize DynASM structures. */
ctx->nglob = GLOB__MAX;
ctx->glob = (void **)malloc(ctx->nglob*sizeof(void *));
+ if (ctx->glob == NULL) { /* malloc() failed, what do we do now? */
+ /* should we print a warning message? */
+ return -1;
+ }
+
memset(ctx->glob, 0, ctx->nglob*sizeof(void *));
ctx->nreloc = 0;
ctx->globnames = globnames;
ctx->relocsym = (const char **)malloc(NRELOCSYM*sizeof(const char *));
+ if (ctx->relocsym == NULL) { /* malloc() failed, what do we do now? */
+ /* should we print a warning message? */
+ return -1;
+ }
ctx->nrelocsym = 0;
for (i = 0; i < (int)NRELOCSYM; i++) relocmap[i] = -1;
@@ -197,13 +210,25 @@
(void)dasm_checkstep(Dst, -1);
if ((status = dasm_link(Dst, &ctx->codesz))) return status;
ctx->code = (uint8_t *)malloc(ctx->codesz);
+ if (ctx->code == NULL) { /* malloc() failed, what do we do now? */
+ /* should we print a warning message? */
+ return -1;
+ }
if ((status = dasm_encode(Dst, (void *)ctx->code))) return status;
/* Allocate symbol table and bytecode offsets. */
ctx->beginsym = sym_decorate(ctx, "", LABEL_PREFIX "vm_asm_begin");
ctx->sym = (BuildSym *)malloc((ctx->npc+ctx->nglob+1)*sizeof(BuildSym));
+ if (ctx->sym == NULL) { /* malloc() failed, what do we do now? */
+ /* should we print a warning message? */
+ return -1;
+ }
ctx->nsym = 0;
ctx->bc_ofs = (int32_t *)malloc(ctx->npc*sizeof(int32_t));
+ if (ctx->bc_ofs == NULL) { /* malloc() failed, what do we do now? */
+ /* should we print a warning message? */
+ return -1;
+ }
/* Collect the opcodes (PC labels). */
for (i = 0; i < ctx->npc; i++) {
I am attaching the patch file to this email.
Bill Parker (wp02855 at gmail dot com)
Attachment:
buildvm.c.patch
Description: Binary data
