dovecot - Jul 2019 - Dovecot 2.3.6 on Solaris10: build issues, segfaults

Looking further into this segfault at

 	settings-parser.c:setting_copy():1519
 	*dest_size = *src_size;

*src_size points to type size_t (typedef unsigned long), a 4-byte
aligned value consistent with a 32-bit build.  This is mismatched with
declared type

 	(gdb) whatis src_size
 	type = const uoff_t *
 	(gdb) whatis uoff_t
 	type = unsigned long long
 	(gdb) p sizeof(uoff_t)
 	$1 = 8

resulting in the segfault when *src_size is dereferened.  The implied
condition of this code segment is typeof(uoff_t)==typeof(size_t) which
is clearly not the case.

I'm not sure how/if uoff_t is defined, but configure reports

 	checking for uoff_t... no
 	checking type of off_t... long long

The latter is weird, because if I compile and run using the same compiler flags

 	#include <stdio.h>
 	int main(void) { printf("%d %d\n",sizeof(long long),sizeof(off_t));
}

the output is "8 4".

Joseph Tam <jtam.home at gmail.com>

Ah, okay, I see. submission_max_mail_size should be defined as uoff_t instead of
size_t in struct submission_settings and struct submission_settings.
> On 20 Jul 2019, at 1.47, Joseph Tam via dovecot <dovecot at
dovecot.org> wrote:
> 
> 
> Looking further into this segfault at
> 
> 	settings-parser.c:setting_copy():1519
> 	*dest_size = *src_size;
> 
> *src_size points to type size_t (typedef unsigned long), a 4-byte
> aligned value consistent with a 32-bit build.  This is mismatched with
> declared type
> 
> 	(gdb) whatis src_size
> 	type = const uoff_t *
> 	(gdb) whatis uoff_t
> 	type = unsigned long long
> 	(gdb) p sizeof(uoff_t)
> 	$1 = 8
> 
> resulting in the segfault when *src_size is dereferened.  The implied
> condition of this code segment is typeof(uoff_t)==typeof(size_t) which
> is clearly not the case.
> 
> I'm not sure how/if uoff_t is defined, but configure reports
> 
> 	checking for uoff_t... no
> 	checking type of off_t... long long
> 
> The latter is weird, because if I compile and run using the same compiler
flags
> 
> 	#include <stdio.h>
> 	int main(void) { printf("%d %d\n",sizeof(long
long),sizeof(off_t)); }
> 
> the output is "8 4".
> 
> Joseph Tam <jtam.home at gmail.com>

On Mon, 22 Jul 2019, Timo Sirainen wrote:
> Ah, okay, I see.  submission_max_mail_size should be defined as uoff_t
> instead of size_t in struct submission_settings and struct
> submission_settings.
Thanks!

This appears to be the correct diagnosis as this patch (for 2.3.7) got
rid of the segfaults

===============================================================================---
a/src/submission-login/submission-login-settings.h	Mon Jul 22 14:37:26 2019
+++ b/src/submission-login/submission-login-settings.h	Mon Jul 22 14:38:16 2019
@@ -7,3 +7,3 @@
  	/* submission: */
-	size_t submission_max_mail_size;
+	uoff_t submission_max_mail_size;
  	const char *submission_backend_capabilities;
--- a/src/submission/submission-settings.h	Mon Jul 22 14:37:17 2019
+++ b/src/submission/submission-settings.h	Mon Jul 22 14:38:06 2019
@@ -22,3 +22,3 @@
  	/* submission: */
-	size_t submission_max_mail_size;
+	uoff_t submission_max_mail_size;
  	unsigned int submission_max_recipients;
===============================================================================
Joseph Tam <jtam.home at gmail.com>