2005-11-21 18:02:27

by folkert

Subject: [2.6.14] bug in inet_connection_sock.c -> lowest port always skipped

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Hi,

There seems to be a small bug in inet_connection_sock.c: the lowest port
set using sysctl (taken from 'sysctl_local_port_range') is always
skipped in the first iteration.
In inet_csk_get_port one can find this:
if (hashinfo->port_rover < low)
rover = low;
else
rover = hashinfo->port_rover;
do {
rover++;
As you can see the first statement is a ++ causing the first port to
always be skipped.
Patch fixing this follows below.

Signed off: Folkert van Heusden <[email protected]>

diff -uNbB inet_connection_sock.c.org inet_connection_sock.c
- --- inet_connection_sock.c.org 2005-11-21 18:52:24.000000000 +0100
+++ inet_connection_sock.c 2005-11-21 18:53:43.000000000 +0100
@@ -86,7 +86,6 @@
else
rover = hashinfo->port_rover;
do {
- - rover++;
if (rover > high)
rover = low;
head = &hashinfo->bhash[inet_bhashfn(rover, hashinfo->bhash_size)];
@@ -97,6 +96,7 @@
break;
next:
spin_unlock(&head->lock);
+ rover++;
} while (--remaining > 0);
hashinfo->port_rover = rover;
spin_unlock(&hashinfo->portalloc_lock);


Folkert van Heusden

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2005-11-21 18:13:10

by Patrick McHardy

Subject: Re: [2.6.14] bug in inet_connection_sock.c -> lowest port always skipped

Folkert van Heusden wrote:
> There seems to be a small bug in inet_connection_sock.c: the lowest port
> set using sysctl (taken from 'sysctl_local_port_range') is always
> skipped in the first iteration.
> In inet_csk_get_port one can find this:
> if (hashinfo->port_rover < low)
> rover = low;
> else
> rover = hashinfo->port_rover;
> do {
> rover++;
> As you can see the first statement is a ++ causing the first port to
> always be skipped.

This has already been fixed three weeks ago by Stephen Hemminger's port
randomization patch.

2005-11-22 11:16:28

by folkert

Subject: Re: [2.6.14] bug in inet_connection_sock.c -> lowest port always skipped

> >There seems to be a small bug in inet_connection_sock.c: the lowest port
> >set using sysctl (taken from 'sysctl_local_port_range') is always
> >skipped in the first iteration.
> >In inet_csk_get_port one can find this:
> > if (hashinfo->port_rover < low)
> > rover = low;
> > else
> > rover = hashinfo->port_rover;
> > do {
> > rover++;
> >As you can see the first statement is a ++ causing the first port to
> >always be skipped.
> This has already been fixed three weeks ago by Stephen Hemminger's port
> randomization patch.

Great!


Folkert van Heusden

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