* Simon Horman [2010-09-26 16:58:05 +0900]:
> On Sat, Sep 25, 2010 at 11:10:53PM +0200, Sergio Gelato wrote:
> > * Simon Horman [2010-09-25 21:34:02 +0900]:
> > > On Fri, Sep 24, 2010 at 10:36:09AM +0200, Sergio Gelato wrote:
> > > > The main problem is that perdition/io.c:io_pipe() and its caller
> > > > perdition/perdition.c:perdition_log_close() use int counters
> > > > while the corresponding arguments in vanessa_socket_pipe_func() 
> > > > are declared size_t. I'd worry about stack corruption on platforms 
> > > > where sizeof(size_t) > sizeof(int).
> > > > 
> > > > Suggested fix: declare those counters size_t, and (for cosmetic 
> > > > purposes)
> > > > cast them to unsigned long before formatting them with %lu instead of 
> > > > %d.
> > > 
> > > Thanks, I'll fix that.
> > > 
> > > Do you think it warrants an update to the testing (= already frozen 
> > > squeeze)
> > > package?
> > 
> > I do: amd64 has sizeof(size_t)==8 and sizeof(int)==4.
> 
> Hi,
> 
> could you take a look at the following patch and see what you think?
> I have isolated three integer/size_t with problems.
> 
> 1) perdition_log_close() takes integer arguments but the counters are
>    actually size_t.
> 
>    I think that the resulting bug is cosmetic.

I stand corrected. On looking more carefully at the various versions of
perdition I'm interested in, I now see that changeset 695 actually did
fix the problem I was most concerned with. (You didn't update the comments,
but that's also cosmetic.) Then I see no need to push this fix into
squeeze. (lenny, on the other hand, might benefit from that changeset 695.)

> 2) __io_pipe_read() and __io_pipe_write() return an int but
>    the counter in question is a ssize_t.
> 
>    I actually don't think this can manifest in a problem as the maximum
>    return value is limited by the count argument, which is 1024
>    (=BUFFER_SIZE).  If count was greater than 2^31 then a problem could
>    occur whereby a large read was mis-read as an error and the connection
>    would be prematurely closed.

I wouldn't be so sure. On platforms where int is shorter than ssize_t,
vanessa_socket_pipe_read_write_func() will use data that may not have been
initialised properly. Even if it has been zeroed, depending on endianness
the effect could be equivalent to a shift, or the result may not be
sign-extended correctly. amd64 seems to fall into this last category:
storing (-1) into %eax zeroes the upper half of %rax, which should
defeat the error handling in your code.

*This* fix would therefore be welcome for squeeze according to my criteria.

> 3) perditiondb_odbc.c:dbserver_get() passes the address of
>    an SQLINTEGER instead of the address of a SQLLEN to the
>    odbc library call SQLBindCol() twice. 
> 
>    This seems like it could cause a stack corruption on
>    systems such as amd64 where SQLINTEGER (= typdef int) is 4 bytes wide
>    but SQLLEN (= typdef long) is 8 bytes wide.

I agree with you here (except that I, and my compiler, count three instances
of the problem, not two; but that doesn't affect the patch). Also a candidate 
for squeeze, I would think.

> Index: perdition/perdition/perdition.c
> ===================================================================
> --- perdition.orig/perdition/perdition.c      2010-09-26 15:42:17.000000000 
> +0900
> +++ perdition/perdition/perdition.c   2010-09-26 15:42:30.000000000 +0900
> @@ -309,14 +309,14 @@ static void perdition_log_close_early(co
>  }
>  
>  static void perdition_log_close(const char *from_to_host_str,
> -                             struct auth *auth, int received, int sent)
> +                             struct auth *auth, size_t received, size_t sent)
>  {
>       struct quoted_str authorisation_id = quote_str(auth->authorisation_id);
>  
>       VANESSA_LOGGER_ERR_UNSAFE("Closing session:%s "
>                                 "authorisation_id=%s%s%s "
>                                 "authentication_id=\"%s\" "
> -                               "received=%d sent=%d",
> +                               "received=%zu sent=%zu",
>                                 from_to_host_str,
>                                 authorisation_id.quote,
>                                 authorisation_id.str,
> Index: perdition/perdition/io.c
> ===================================================================
> --- perdition.orig/perdition/io.c     2010-09-26 15:42:17.000000000 +0900
> +++ perdition/perdition/io.c  2010-09-26 15:55:41.000000000 +0900
> @@ -655,7 +655,7 @@ err:
>   *         0 otherwise (one of io_a or io_b closes gracefully)
>   **********************************************************************/
>  
> -static int __io_pipe_read(int fd, void *buf, size_t count, void *data){
> +static ssize_t __io_pipe_read(int fd, void *buf, size_t count, void *data){
>    io_t *io;
>    io_select_t *s;
>    ssize_t bytes;
> @@ -693,7 +693,9 @@ err:
>  }
>           
>  
> -static int __io_pipe_write(int fd, const void *buf, size_t count, void 
> *data){
> +static ssize_t
> +__io_pipe_write(int fd, const void *buf, size_t count, void *data)
> +{
>    io_t *io;
>    io_select_t *s;
>  
> Index: perdition/perdition/db/odbc/perditiondb_odbc.c
> ===================================================================
> --- perdition.orig/perdition/db/odbc/perditiondb_odbc.c       2010-09-26 
> 15:42:17.000000000 +0900
> +++ perdition/perdition/db/odbc/perditiondb_odbc.c    2010-09-26 
> 15:42:30.000000000 +0900
> @@ -214,7 +214,7 @@ int dbserver_get(const char *key_str, co
>               char **str_return, size_t * len_return)
>  {
>       SQLINTEGER rc;
> -     SQLINTEGER rc2;
> +     SQLLEN rc2;
>       int status = -1;
>       SQLHENV env;
>       SQLHDBC hdbc;



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