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PPC: CHRP - fix possible NULL pointer dereference

PATCH In review Cyrill Gorcunov 2 participants 4 messages Nov 22, 2007 – Nov 23, 2007 PowerPC

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Cyrill Gorcunov

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#0 lore raw

PATCH 1/1 PPC: CHRP - fix possible NULL pointer dereference

From: Cyrill Gorcunov <[email protected]>

This patch does fix possible NULL pointer dereference inside of strncmp() if of_get_property() failed.

Signed-off-by Cyrill Gorcunov <[email protected]>

---

 arch/powerpc/platforms/chrp/setup.c |   23 +++++++++++++----------
 1 files changed, 13 insertions(+), 10 deletions(-)
arch/powerpc/platforms/chrp/setup.c +13 -10
index 5930626..e3f276d 100644
@@ -115,7 +115,7 @@ void chrp_show_cpuinfo(struct seq_file *m)
 	seq_printf(m, "machine\t\t: CHRP %s\n", model);
 
 	/* longtrail (goldengate) stuff */
-	if (!strncmp(model, "IBM,LongTrail", 13)) {
+	if (model && !strncmp(model, "IBM,LongTrail", 13)) {
 		/* VLSI VAS96011/12 `Golden Gate 2' */
 		/* Memory banks */
 		sdramen = (in_le32(gg2_pci_config_base + GG2_PCI_DRAM_CTRL)

@@ -203,16 +203,19 @@ static void __init sio_fixup_irq(const char *name, u8 device, u8 level,
 static void __init sio_init(void)
 {
 	struct device_node *root;
+	const char *model = NULL;
 
-	if ((root = of_find_node_by_path("/")) &&
-	    !strncmp(of_get_property(root, "model", NULL),
-			"IBM,LongTrail", 13)) {
-		/* logical device 0 (KBC/Keyboard) */
-		sio_fixup_irq("keyboard", 0, 1, 2);
-		/* select logical device 1 (KBC/Mouse) */
-		sio_fixup_irq("mouse", 1, 12, 2);
-	}
-	of_node_put(root);
+	root = of_find_node_by_path("/");
+	if (root) {
+		model = of_get_property(root, "model", NULL);
+		if (model && !strncmp(model,"IBM,LongTrail", 13)) {
+			/* logical device 0 (KBC/Keyboard) */
+			sio_fixup_irq("keyboard", 0, 1, 2);
+			/* select logical device 1 (KBC/Mouse) */
+			sio_fixup_irq("mouse", 1, 12, 2);
+		}
+		of_node_put(root);
+ 	}
 }
#1 lore raw
Quoted 3 lines · On Thu, 22 Nov 2007 22:54:23 +0300 Cyrill Gorcunov <[email protected]> wrote:

This patch does fix possible NULL pointer dereference inside of strncmp() if of_get_property() failed.

Thanks for this.

arch/powerpc/platforms/chrp/setup.c static void __init sio_fixup_irq(const char *name, u8 device, u8 level, · line 206

Quoted 4 lines

static void __init sio_init(void)
{

arch/powerpc/platforms/chrp/setup.c +1 -0
 	struct device_node *root;
+	const char *model = NULL;

You don't need this initialization as you always assign the variable before you use it.

arch/powerpc/platforms/chrp/setup.c static void __init sio_fixup_irq(const char *name, u8 device, u8 level, · line 209

Quoted 2 lines
arch/powerpc/platforms/chrp/setup.c +2 -0
+	root = of_find_node_by_path("/");
+	if (root) {

	if (!root)
		return;

would save a level of indentation. Not important.

Signature · 3 lines
Cheers,
Stephen Rothwell                    [email protected]
http://www.canb.auug.org.au/~sfr/
author
#2 lore raw
Quoted 22 lines · Stephen Rothwell
Quoted 3 lines · On Thu, 22 Nov 2007 22:54:23 +0300 Cyrill Gorcunov <[email protected]> wrote:

This patch does fix possible NULL pointer dereference inside of strncmp() if of_get_property() failed.

Thanks for this.

Quoted 4 lines

static void __init sio_init(void)
{
struct device_node *root;
+ const char *model = NULL;

You don't need this initialization as you always assign the variable before you use it.

Quoted 2 lines

+ root = of_find_node_by_path("/");
+ if (root) {

if (!root)
return;

Quoted 7 lines

would save a level of indentation. Not important.

--
Cheers,
Stephen Rothwell [email protected]
http://www.canb.auug.org.au/~sfr/

Oh my :) Thanks. I'll fix it and resend.

author
#3 lore raw
In reply to Stephen Rothwell

Here is updated version
---
From: Cyrill Gorcunov <[email protected]>

This patch does fix possible NULL pointer dereference inside of strncmp() if of_get_property() failed.

Signed-off-by Cyrill Gorcunov <[email protected]>

---

 arch/powerpc/platforms/chrp/setup.c |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)
arch/powerpc/platforms/chrp/setup.c +9 -4
index 5930626..da4e45e 100644
@@ -115,7 +115,7 @@ void chrp_show_cpuinfo(struct seq_file *m)
 	seq_printf(m, "machine\t\t: CHRP %s\n", model);
 
 	/* longtrail (goldengate) stuff */
-	if (!strncmp(model, "IBM,LongTrail", 13)) {
+	if (model && !strncmp(model, "IBM,LongTrail", 13)) {
 		/* VLSI VAS96011/12 `Golden Gate 2' */
 		/* Memory banks */
 		sdramen = (in_le32(gg2_pci_config_base + GG2_PCI_DRAM_CTRL)

@@ -203,15 +203,20 @@ static void __init sio_fixup_irq(const char *name, u8 device, u8 level,
 static void __init sio_init(void)
 {
 	struct device_node *root;
+	const char *model;
 
-	if ((root = of_find_node_by_path("/")) &&
-	    !strncmp(of_get_property(root, "model", NULL),
-			"IBM,LongTrail", 13)) {
+	root = of_find_node_by_path("/");
+	if (!root)
+		return;
+
+	model = of_get_property(root, "model", NULL);
+	if (model && !strncmp(model,"IBM,LongTrail", 13)) {
 		/* logical device 0 (KBC/Keyboard) */
 		sio_fixup_irq("keyboard", 0, 1, 2);
 		/* select logical device 1 (KBC/Mouse) */
 		sio_fixup_irq("mouse", 1, 12, 2);
 	}
+
 	of_node_put(root);
 }