From: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
To: Herbert Xu <herbert@gondor.apana.org.au>
Cc: "David S. Miller" <davem@davemloft.net>,
netdev@vger.kernel.org, Eugene Kapun <abacabadabacaba@gmail.com>,
maxk@qualcomm.com, linux-net@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: PROBLEM: tun/tap crashes if open() /dev/net/tun and then poll() it.
Date: Mon, 6 Jul 2009 07:48:35 +0200 [thread overview]
Message-ID: <20090706074835.3fe641f0@mako-desktop> (raw)
In-Reply-To: <20090706011230.GC15156@gondor.apana.org.au>
On Mon, 6 Jul 2009 09:12:30 +0800
Herbert Xu <herbert@gondor.apana.org.au> wrote:
> On Mon, Jul 06, 2009 at 12:11:14AM +0200, Mariusz Kozlowski wrote:
> >
> > Can you try this patch?
...
> Good catch. Can you please resend with a sign-off?
Sure. Just wanted to wait for confirmation from Eugene.
Fix NULL pointer dereference in tun_chr_pool() introduced by
commit 33dccbb050bbe35b88ca8cf1228dcf3e4d4b3554 and triggered
by this code:
int fd;
struct pollfd pfd;
fd = open("/dev/net/tun", O_RDWR);
pfd.fd = fd;
pfd.events = POLLIN | POLLOUT;
poll(&pfd, 1, 0);
Reported-by: Eugene Kapun <abacabadabacaba@gmail.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a1b0697..bcbb25e 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -482,12 +482,14 @@ static unsigned int tun_chr_poll(struct file *file, poll_table * wait)
{
struct tun_file *tfile = file->private_data;
struct tun_struct *tun = __tun_get(tfile);
- struct sock *sk = tun->sk;
+ struct sock *sk;
unsigned int mask = 0;
if (!tun)
return POLLERR;
+ sk = tun->sk;
+
DBG(KERN_INFO "%s: tun_chr_poll\n", tun->dev->name);
poll_wait(file, &tfile->read_wait, wait);
next prev parent reply other threads:[~2009-07-06 5:48 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-07-04 8:36 PROBLEM: tun/tap crashes if open() /dev/net/tun and then poll() it Eugene Kapun
2009-07-05 22:11 ` Mariusz Kozlowski
2009-07-06 1:12 ` Herbert Xu
2009-07-06 5:48 ` Mariusz Kozlowski [this message]
2009-07-06 20:08 ` David Miller
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