Re: Dovecot 2.3.6 on Solaris10: build issues, segfaults

[Timo Sirainen via dovecot]

On 9 Jul 2019, at 3.02, Joseph Tam via dovecot <dovecot@dovecot.org> wrote:
> 
> Issue 3) dovecot/doveconf segfaults on startup
> 
>       It crashes here while processing dovecot.conf, as does "doveconf"
> 
>               (settings-parser.c:1519 in setting_copy())
>               *dest_size = *src_size;

This is correct code.

>       It appears *src_size is not an 8-byte address aligned (0x5597c).
>       It inherits this value from the calling routine as the sum of
>       "set" (8-byte aligned) + "def->offset"=20 => misaligned address.
> 
>               (settings-parser.c:1597 in settings_dup_full())
>               src = CONST_PTR_OFFSET(set, def->offset);
> 
>               (gdb) p set
>               $2 = (const void *) 0x55968
>               (gdb) p *def
>               $3 = {type = SET_SIZE, key = 0x2d548 
> "submission_max_mail_size", offset = 20, list_info = 0x0}

This is unexpected. But I don't see how it's a Dovecot bug. It seems as if your 
compiler doesn't do padding correctly and then crashes because it didn't do it 
correctly. I guess you're compiling this as 32bit? Is size_t 32bit or 64bit?

Can you try with the below small test program if it prints the same 20?

#include <stdio.h>
#include <stdbool.h>
#include <stddef.h>

#define in_port_t unsigned short

struct submission_settings {
        bool verbose_proctitle;
        const char *rawlog_dir;

        const char *hostname;

        const char *login_greeting;
        const char *login_trusted_networks;

        /* submission: */
        size_t submission_max_mail_size;
        unsigned int submission_max_recipients;
        const char *submission_client_workarounds;
        const char *submission_logout_format;

        /* submission backend: */
        const char *submission_backend_capabilities;

        /* submission relay: */
        const char *submission_relay_host;
        in_port_t submission_relay_port;
        bool submission_relay_trusted;

        const char *submission_relay_user;
        const char *submission_relay_master_user;
        const char *submission_relay_password;

        const char *submission_relay_ssl;
        bool submission_relay_ssl_verify;

        const char *submission_relay_rawlog_dir;
        unsigned int submission_relay_max_idle_time;

        unsigned int submission_relay_connect_timeout;
        unsigned int submission_relay_command_timeout;

        /* imap urlauth: */
        const char *imap_urlauth_host;
        in_port_t imap_urlauth_port;

        int parsed_workarounds;
};

int main(void)
{
        struct submission_settings set;

        printf("offset = %ld\n", offsetof(struct submission_settings, 
submission_max_mail_size));
        printf("size = %ld\n", sizeof(set.submission_max_mail_size));
        return 0;
}