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From: David Woodhouse <dwmw2@infradead.org>
To: netdev@vger.kernel.org
Cc: chas@cmf.nrl.navy.mil, krzysiek@podlesie.net,
	David Woodhouse <David.Woodhouse@intel.com>
Subject: [PATCH 11/17] br2684: fix module_put() race
Date: Fri, 30 Nov 2012 00:35:30 +0000	[thread overview]
Message-ID: <1354235736-26833-12-git-send-email-dwmw2@infradead.org> (raw)
In-Reply-To: <1354235736-26833-1-git-send-email-dwmw2@infradead.org>

From: David Woodhouse <David.Woodhouse@intel.com>

The br2684 code used module_put() during unassignment from vcc with
hope that we have BKL. This assumption is no longer true.

Now owner field in atmvcc is used to move this module_put()
to vcc_destroy_socket().

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
Acked-by: Krzysztof Mazur <krzysiek@podlesie.net>
---
 net/atm/br2684.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/net/atm/br2684.c b/net/atm/br2684.c
index c483021..373d784 100644
--- a/net/atm/br2684.c
+++ b/net/atm/br2684.c
@@ -68,6 +68,7 @@ struct br2684_vcc {
 	/* keep old push, pop functions for chaining */
 	void (*old_push)(struct atm_vcc *vcc, struct sk_buff *skb);
 	void (*old_pop)(struct atm_vcc *vcc, struct sk_buff *skb);
+	struct module *old_owner;
 	enum br2684_encaps encaps;
 	struct list_head brvccs;
 #ifdef CONFIG_ATM_BR2684_IPFILTER
@@ -385,8 +386,8 @@ static void br2684_close_vcc(struct br2684_vcc *brvcc)
 	write_unlock_irq(&devs_lock);
 	brvcc->atmvcc->user_back = NULL;	/* what about vcc->recvq ??? */
 	brvcc->old_push(brvcc->atmvcc, NULL);	/* pass on the bad news */
+	module_put(brvcc->old_owner);
 	kfree(brvcc);
-	module_put(THIS_MODULE);
 }
 
 /* when AAL5 PDU comes in: */
@@ -560,9 +561,11 @@ static int br2684_regvcc(struct atm_vcc *atmvcc, void __user * arg)
 	brvcc->encaps = (enum br2684_encaps)be.encaps;
 	brvcc->old_push = atmvcc->push;
 	brvcc->old_pop = atmvcc->pop;
+	brvcc->old_owner = atmvcc->owner;
 	barrier();
 	atmvcc->push = br2684_push;
 	atmvcc->pop = br2684_pop;
+	atmvcc->owner = THIS_MODULE;
 
 	/* initialize netdev carrier state */
 	if (atmvcc->dev->signal == ATM_PHY_SIG_LOST)
-- 
1.8.0

  parent reply	other threads:[~2012-11-30  0:36 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-11-30  0:35 [PATCH 00/17] ATM fixes for pppoatm/br2684 David Woodhouse
2012-11-30  0:35 ` [PATCH 01/17] atm: add owner of push() callback to atmvcc David Woodhouse
2012-11-30  0:35 ` [PATCH 02/17] pppoatm: allow assign only on a connected socket David Woodhouse
2012-11-30  0:35 ` [PATCH 03/17] pppoatm: fix module_put() race David Woodhouse
2012-11-30  0:35 ` [PATCH 04/17] pppoatm: take ATM socket lock in pppoatm_send() David Woodhouse
2012-11-30  0:35 ` [PATCH 05/17] pppoatm: drop frames to not-ready vcc David Woodhouse
2012-11-30 10:27   ` Krzysztof Mazur
2012-11-30  0:35 ` [PATCH 06/17] pppoatm: do not inline pppoatm_may_send() David Woodhouse
2012-11-30  0:35 ` [PATCH 07/17] solos-pci: Wait for pending TX to complete when releasing vcc David Woodhouse
2012-12-02  0:17   ` [PATCH v2 " David Woodhouse
2012-11-30  0:35 ` [PATCH 08/17] br2684: don't send frames on not-ready vcc David Woodhouse
2012-11-30  0:35 ` [PATCH 09/17] atm: Add release_cb() callback to vcc David Woodhouse
2012-11-30  0:35 ` [PATCH 10/17] pppoatm: fix missing wakeup in pppoatm_send() David Woodhouse
2012-11-30  0:35 ` David Woodhouse [this message]
2012-11-30  0:35 ` [PATCH 12/17] solos-pci: Fix leak of skb received for unknown vcc David Woodhouse
2012-11-30  0:35 ` [PATCH 13/17] br2684: allow assign only on a connected socket David Woodhouse
2012-11-30  0:35 ` [PATCH 14/17] pppoatm: optimise PPP channel wakeups after sock_owned_by_user() David Woodhouse
2012-11-30  0:35 ` [PATCH 15/17] solos-pci: clean up pclose() function David Woodhouse
2012-11-30  0:35 ` [PATCH 16/17] solos-pci: use GFP_KERNEL where possible, not GFP_ATOMIC David Woodhouse
2012-11-30  0:35 ` [PATCH 17/17] solos-pci: remove list_vccs() debugging function David Woodhouse
2012-11-30 10:44 ` [PATCH 00/17] ATM fixes for pppoatm/br2684 Krzysztof Mazur
2012-11-30 20:22   ` David Woodhouse
2012-12-01 16:43     ` David Miller
2012-12-01 16:44       ` David Miller
2012-12-01 16:48         ` David Woodhouse
2012-12-01 17:02           ` Chas Williams (CONTRACTOR)
2012-12-01 17:21             ` David Woodhouse
2012-12-02  1:57               ` Chas Williams (CONTRACTOR)
2012-12-02  2:17                 ` David Miller
2012-12-01 17:33         ` David Woodhouse
2012-12-02  0:40           ` David Woodhouse
2012-12-02  1:49             ` David Miller
2012-12-02  8:14               ` David Woodhouse
2012-12-02 21:29                 ` Checking struct size against sizeof(skb->cb) (was Re: [PATCH 00/17] ATM fixes for pppoatm/br2684) David Woodhouse
2012-12-20 14:03               ` skb->cb size checks " David Woodhouse
2012-12-02  0:35         ` [PATCH 00/17] ATM fixes for pppoatm/br2684 David Woodhouse
2012-12-02  1:47           ` David Miller

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