Re: _FORTIFY_SOURCE=3 causes latest Samba builds to core dump...

Looking at this a bit more at least one of my core dumps are “fun” :-). It core dumps on recvfrom() in samba:
The reason for the crash in recvfrom() is that on FreeBSD the 'struct sockaddr' definition is the old classical one:

struct sockaddr {
        unsigned char   sa_len;         /* total length */
        sa_family_t     sa_family;      /* address family */
        char            sa_data[14];    /* actually longer; address value */
};


whereas Linux uses:

struct sockaddr {
        sa_family_t     sa_family;      /* address family, AF_xxx       */
        union {
                char sa_data_min[14];           /* Minimum 14 bytes of protocol address */
                DECLARE_FLEX_ARRAY(char, sa_data);
        };
};


and the code in lib/tsocket/tsocket_bsd.c:tdgram_bsd_recvfrom_handler() uses:

       ZERO_STRUCTP(bsda);
        bsda->sa_socklen = sizeof(bsda->u.ss);
#ifdef HAVE_STRUCT_SOCKADDR_SA_LEN
        bsda->u.sa.sa_len = bsda->sa_socklen;
#endif

        ret = recvfrom(bsds->fd, state->buf, state->len, 0,
                       &bsda->u.sa, &bsda->sa_socklen);


and thus it will fail due to sizeof(bsda->u.sa <http://u.sa/>) < bsda->sa_socklen...

One could probably fix this by addding a 'char dummy[]' array to the definition of struct sockaddr in BSD's header files similar to the Linux one (probably).

Or patch Samba to use (struct sockaddr *) &bsda->u.ss instead of ->u.sa (and find all other similar cases in the code) probably...

Hmm.. :-)
- Peter
> On 24 Apr 2026, at 17:00, Peter Eriksson <[email protected]> wrote:
> 
> Which isn’t so surprising since it seems that FreeBSD’s own implementation (ssp) doesn’t support _FORTIFY_SOURCE=3. 
> 
> Are there any plans of updating this that anyone know of?
> 
> (For others attempting to build Samba 4.24.1 och 4.23.7 - just edit buildtools/wafsamba/samba_autoconf and change 3 to 1)
> 
> - Peter
> 
>