[PATCH 1/4] mtd: mxc_nand: avoid NULL pointer dereference

[PATCH 1/4] mtd: mxc_nand: avoid NULL pointer dereference

[Alexander Beregalov]

Assign nand_chip and host only if host is not NULL.

Cc: David Woodhouse <dwmw2@infradead.org>
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
---
 drivers/mtd/nand/mxc_nand.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/mtd/nand/mxc_nand.c b/drivers/mtd/nand/mxc_nand.c
index 45dec57..4ace54c 100644
--- a/drivers/mtd/nand/mxc_nand.c
+++ b/drivers/mtd/nand/mxc_nand.c
@@ -881,12 +881,14 @@ static int __devexit mxcnd_remove(struct platform_device *pdev)
 static int mxcnd_suspend(struct platform_device *pdev, pm_message_t state)
 {
 	struct mtd_info *mtd = platform_get_drvdata(pdev);
-	struct nand_chip *nand_chip = mtd->priv;
-	struct mxc_nand_host *host = nand_chip->priv;
+	struct nand_chip *nand_chip;
+	struct mxc_nand_host *host;
 	int ret = 0;
 
 	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND suspend\n");
 	if (mtd) {
+		nand_chip = mtd->priv;
+		host = nand_chip->priv;
 		ret = mtd->suspend(mtd);
 		/* Disable the NFC clock */
 		clk_disable(host->clk);
@@ -898,13 +900,15 @@ static int mxcnd_suspend(struct platform_device *pdev, pm_message_t state)
 static int mxcnd_resume(struct platform_device *pdev)
 {
 	struct mtd_info *mtd = platform_get_drvdata(pdev);
-	struct nand_chip *nand_chip = mtd->priv;
-	struct mxc_nand_host *host = nand_chip->priv;
+	struct nand_chip *nand_chip;
+	struct mxc_nand_host *host;
 	int ret = 0;
 
 	DEBUG(MTD_DEBUG_LEVEL0, "MXC_ND : NAND resume\n");
 
 	if (mtd) {
+		nand_chip = mtd->priv;
+		host = nand_chip->priv;
 		/* Enable the NFC clock */
 		clk_enable(host->clk);
 		mtd->resume(mtd);
-- 
1.6.6

[PATCH 2/4] SCSI: pm8001: avoid NULL pointer dereference

[Alexander Beregalov]

Assign device_id only if pm8001_dev is not NULL.

Cc: James Bottomley <James.Bottomley@suse.de>
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
---
 drivers/scsi/pm8001/pm8001_sas.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
index 7f9c83a..4e748d1 100644
--- a/drivers/scsi/pm8001/pm8001_sas.c
+++ b/drivers/scsi/pm8001/pm8001_sas.c
@@ -884,11 +884,12 @@ static void pm8001_dev_gone_notify(struct domain_device *dev)
 	u32 tag;
 	struct pm8001_hba_info *pm8001_ha;
 	struct pm8001_device *pm8001_dev = dev->lldd_dev;
-	u32 device_id = pm8001_dev->device_id;
+	u32 device_id;
 	pm8001_ha = pm8001_find_ha_by_dev(dev);
 	spin_lock_irqsave(&pm8001_ha->lock, flags);
 	pm8001_tag_alloc(pm8001_ha, &tag);
 	if (pm8001_dev) {
+		device_id = pm8001_dev->device_id;
 		PM8001_DISC_DBG(pm8001_ha,
 			pm8001_printk("found dev[%d:%x] is gone.\n",
 			pm8001_dev->device_id, pm8001_dev->dev_type));
-- 
1.6.6

[PATCH 3/4] ISDN: hysdn: avoid NULL pointer dereference

[Alexander Beregalov]

Assign dev only if lp is not NULL.

Cc: Armin Schindler <mac@melware.de>
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
---
 drivers/isdn/hysdn/hysdn_net.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/isdn/hysdn/hysdn_net.c b/drivers/isdn/hysdn/hysdn_net.c
index 72eb926..feec8d8 100644
--- a/drivers/isdn/hysdn/hysdn_net.c
+++ b/drivers/isdn/hysdn/hysdn_net.c
@@ -187,12 +187,13 @@ void
 hysdn_rx_netpkt(hysdn_card * card, unsigned char *buf, unsigned short len)
 {
 	struct net_local *lp = card->netif;
-	struct net_device *dev = lp->dev;
+	struct net_device *dev;
 	struct sk_buff *skb;
 
 	if (!lp)
 		return;		/* non existing device */
 
+	dev = lp->dev;
 	dev->stats.rx_bytes += len;
 
 	skb = dev_alloc_skb(len);
-- 
1.6.6

[PATCH 4/4] uml: line.c: avoid NULL pointer dereference

[Alexander Beregalov]

Assign tty only if line is not NULL.

Cc: Jeff Dike <jdike@addtoit.com>
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
---
 arch/um/drivers/line.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/arch/um/drivers/line.c b/arch/um/drivers/line.c
index cf8a97f..8ebdc8c 100644
--- a/arch/um/drivers/line.c
+++ b/arch/um/drivers/line.c
@@ -18,9 +18,10 @@ static irqreturn_t line_interrupt(int irq, void *data)
 {
 	struct chan *chan = data;
 	struct line *line = chan->line;
-	struct tty_struct *tty = line->tty;
+	struct tty_struct *tty;
 
 	if (line)
+		tty = line->tty;
 		chan_interrupt(&line->chan_list, &line->task, tty, irq);
 	return IRQ_HANDLED;
 }
-- 
1.6.6

Re: [PATCH 4/4] uml: line.c: avoid NULL pointer dereference

[Jeff Dike]

On Thu, Jan 07, 2010 at 04:48:41AM +0300, Alexander Beregalov wrote:
> Assign tty only if line is not NULL.

>  	if (line)
> +		tty = line->tty;
>  		chan_interrupt(&line->chan_list, &line->task, tty, irq);
>  	return IRQ_HANDLED;

Even if the thinking is correct, aren't you missing some braces?

				Jeff

Re: [PATCH 4/4] uml: line.c: avoid NULL pointer dereference

[Alexander Beregalov]

2010/1/7 Jeff Dike <jdike@addtoit.com>:
> On Thu, Jan 07, 2010 at 04:48:41AM +0300, Alexander Beregalov wrote:
>> Assign tty only if line is not NULL.
>
>>       if (line)
>> +             tty = line->tty;
>>               chan_interrupt(&line->chan_list, &line->task, tty, irq);
>>       return IRQ_HANDLED;
>
> Even if the thinking is correct, aren't you missing some braces?

Oops, sorry, I will send another version.