[PATCH] PPC: CHRP - fix possible NULL pointer dereference

[Cyrill Gorcunov]

From: Cyrill Gorcunov <gorc...@gmail.com>

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

Signed-off-by: Cyrill Gorcunov <gorc...@gmail.com>
---

arch/powerpc/platforms/chrp/setup.c | 23 +++++++++++++----------
1 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/arch/powerpc/platforms/chrp/setup.c b/arch/powerpc/platforms/chrp/setup.c
index 5930626..e3f276d 100644
--- a/arch/powerpc/platforms/chrp/setup.c
+++ b/arch/powerpc/platforms/chrp/setup.c
@@ -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);
+ }
}


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majo...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

[Stephen Rothwell]

On Thu, 22 Nov 2007 22:54:23 +0300 Cyrill Gorcunov <gorc...@gmail.com> wrote:
>
> This patch does fix possible NULL pointer dereference
> inside of strncmp() if of_get_property() failed.

Thanks for this.

> 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.

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

if (!root)
return;

would save a level of indentation. Not important.

--
Cheers,
Stephen Rothwell s...@canb.auug.org.au
http://www.canb.auug.org.au/~sfr/

[Cyrill Gorcunov]

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

[Cyrill Gorcunov]

Here is updated version
---
From: Cyrill Gorcunov <gorc...@gmail.com>

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

Signed-off-by: Cyrill Gorcunov <gorc...@gmail.com>
---