Linux wireless drivers development
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From: Malcolm Priestley <tvboxspy@gmail.com>
To: gregkh@linuxfoundation.org
Cc: linux-wireless@vger.kernel.org
Subject: [PATCH ] staging: vt6656: rxtx.c [BUG] s_vGetFreeContext dead lock on null apTD.
Date: Sun, 22 Sep 2013 20:15:58 +0100	[thread overview]
Message-ID: <1379877358.6139.31.camel@canaries32-MCP7A> (raw)

There seems to be race condition that the device is ndo_start_xmit
at a point where the device is closing and apTD is NULL resulting
in dead lock.

Add a NULL check to apTD and return NULL to calling functions.

This is more likely on 64 bit systems.

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
---
 drivers/staging/vt6656/rxtx.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/staging/vt6656/rxtx.c b/drivers/staging/vt6656/rxtx.c
index fb743a8..14f3e85 100644
--- a/drivers/staging/vt6656/rxtx.c
+++ b/drivers/staging/vt6656/rxtx.c
@@ -148,6 +148,8 @@ static void *s_vGetFreeContext(struct vnt_private *pDevice)
     DBG_PRT(MSG_LEVEL_DEBUG, KERN_INFO"GetFreeContext()\n");
 
     for (ii = 0; ii < pDevice->cbTD; ii++) {
+	if (!pDevice->apTD[ii])
+		return NULL;
         pContext = pDevice->apTD[ii];
         if (pContext->bBoolInUse == false) {
             pContext->bBoolInUse = true;
-- 
1.8.3.2


                 reply	other threads:[~2013-09-22 19:16 UTC|newest]

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