2013-09-22 19:16:10

by Malcolm Priestley

[permalink] [raw]
Subject: [PATCH ] staging: vt6656: rxtx.c [BUG] s_vGetFreeContext dead lock on null apTD.

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 <[email protected]>
---
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