[PATCH 5.4 130/344] fore200e: Fix incorrect checks of NULL pointer dereference

Greg Kroah-Hartman
2020-02-21T08:36:16Z

From: Aditya Pakki <pakki001@umn.edu>

[ Upstream commit bbd20c939c8aa3f27fa30e86691af250bf92973a ]

In fore200e_send and fore200e_close, the pointers from the arguments
are dereferenced in the variable declaration block and then checked
for NULL. The patch fixes these issues by avoiding NULL pointer
dereferences.

Signed-off-by: Aditya Pakki <pakki001@umn.edu>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/atm/fore200e.c | 25 ++++++++++++++++++-------
1 file changed, 18 insertions(+), 7 deletions(-)

diff --git a/drivers/atm/fore200e.c b/drivers/atm/fore200e.c
index f1a5002053132..8fbd36eb89410 100644
--- a/drivers/atm/fore200e.c
+++ b/drivers/atm/fore200e.c
@@ -1414,12 +1414,14 @@ fore200e_open(struct atm_vcc *vcc)
static void
fore200e_close(struct atm_vcc* vcc)
{
- struct fore200e* fore200e = FORE200E_DEV(vcc->dev);
struct fore200e_vcc* fore200e_vcc;
+ struct fore200e* fore200e;
struct fore200e_vc_map* vc_map;
unsigned long flags;

ASSERT(vcc);
+ fore200e = FORE200E_DEV(vcc->dev);
+
ASSERT((vcc->vpi >= 0) && (vcc->vpi < 1<<FORE200E_VPI_BITS));
ASSERT((vcc->vci >= 0) && (vcc->vci < 1<<FORE200E_VCI_BITS));

@@ -1464,10 +1466,10 @@ fore200e_close(struct atm_vcc* vcc)
static int
fore200e_send(struct atm_vcc *vcc, struct sk_buff *skb)
{
- struct fore200e* fore200e = FORE200E_DEV(vcc->dev);
- struct fore200e_vcc* fore200e_vcc = FORE200E_VCC(vcc);
+ struct fore200e* fore200e;
+ struct fore200e_vcc* fore200e_vcc;
struct fore200e_vc_map* vc_map;
- struct host_txq* txq = &fore200e->host_txq;
+ struct host_txq* txq;
struct host_txq_entry* entry;
struct tpd* tpd;
struct tpd_haddr tpd_haddr;
@@ -1480,9 +1482,18 @@ fore200e_send(struct atm_vcc *vcc, struct sk_buff *skb)
unsigned char* data;
unsigned long flags;

- ASSERT(vcc);
- ASSERT(fore200e);
- ASSERT(fore200e_vcc);
+ if (!vcc)
+ return -EINVAL;
+
+ fore200e = FORE200E_DEV(vcc->dev);
+ fore200e_vcc = FORE200E_VCC(vcc);
+
+ if (!fore200e)
+ return -EINVAL;
+
+ txq = &fore200e->host_txq;
+ if (!fore200e_vcc)
+ return -EINVAL;

if (!test_bit(ATM_VF_READY, &vcc->flags)) {
DPRINTK(1, "VC %d.%d.%d not ready for tx\n", vcc->itf, vcc->vpi, vcc->vpi);
--
2.20.1