Re: [Tarantool-patches] [PATCH] cppcheck: src/lua/fiber.c null pointer dereference

[Sergey Kaplun <skaplun@tarantool.org>]

On 21.09.20, Sergey Kaplun wrote:
> Found and fixed possible null pointer dereference with cppcheck:
> 
> [src/lua/fiber.c:245] -> [src/lua/fiber.c:217]: (warning) Either the condition 'if(func)' is redundant or there is possible null pointer dereference: func.
> ---
> 
> Branch: https://github.com/tarantool/tarantool/tree/skaplun/cppcheck-lua-fiber-possible-null-pointer-dereference
> 
>  src/lua/fiber.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/lua/fiber.c b/src/lua/fiber.c
> index 45bc03787..bb6212b24 100644
> --- a/src/lua/fiber.c
> +++ b/src/lua/fiber.c
> @@ -214,7 +214,7 @@ fiber_backtrace_cb(int frameno, void *frameret, const char *func, size_t offset,
>  {
>  	struct lua_fiber_tb_ctx *tb_ctx = (struct lua_fiber_tb_ctx *)cb_ctx;
>  	struct lua_State *L = tb_ctx->L;
> -	if (strstr(func, "lj_BC_FUNCC") == func) {
> +	if (func && strstr(func, "lj_BC_FUNCC") == func) {
>  		/* We are in the LUA vm. */
>  		lua_Debug ar;
>  		while (tb_ctx->R && lua_getstack(tb_ctx->R, tb_ctx->lua_frame, &ar) > 0) {
> -- 
> 2.28.0
> 
Since we don't have 'cppcheck' subsystem, I've changed it to 'fiber'.

I've updated commit message to:
```
fiber: src/lua/fiber.c null pointer dereference

Found and fixed possible null pointer dereference with cppcheck:

[src/lua/fiber.c:245] -> [src/lua/fiber.c:217]: (warning) Either the condition 'if(func)' is redundant or there is possible null pointer dereference: func.
```
and pushed it to the branch.


-- 
Best regards,
Sergey Kaplun