Potential free uninitialized pointer in kern_ktrace.c

[Mark Latimer]

Hello,

reading through the compiler warnings I believe there is a potential issue
in /usr/src/sys/kern/kern_ktrace.c At first glance it appears to free
an uninitialized pointer memp.

Regards

int
ktruser(struct proc *p, const char *id, const void *addr, size_t len)
{
        struct ktr_header kth;
        struct ktr_user ktp;
        int error;
//uninitalized
        void *memp;
#define STK_PARAMS      128
        long long stkbuf[STK_PARAMS / sizeof(long long)];

        if (!KTRPOINT(p, KTR_USER))
                return (0);
        if (len > KTR_USER_MAXLEN)
                return (EINVAL);

        atomic_setbits_int(&p->p_flag, P_INKTR);
        ktrinitheader(&kth, p, KTR_USER);
        memset(ktp.ktr_id, 0, KTR_USER_MAXIDLEN);
        error = copyinstr(id, ktp.ktr_id, KTR_USER_MAXIDLEN, NULL);
//if error then skip setting memp
        if (error)
                goto out;

        if (len > sizeof(stkbuf))
                memp = malloc(len, M_TEMP, M_WAITOK);
        else
                memp = stkbuf;
        error = copyin(addr, memp, len);
        if (error)
                goto out;

        ktrwrite2(p, &kth, &ktp, sizeof(ktp), memp, len);
out:
// frees the uninitialized pointer
        if (memp != stkbuf)
                free(memp, M_TEMP, len);