From: Vitaly Mayatskikh <vmayatsk@redhat.com> Date: Sat, 2 Feb 2008 12:43:36 +0100 Subject: [ppc] chrp: fix possible strncmp NULL pointer usage Message-id: m363x7a8if.fsf@dhcp-lab-230.englab.brq.redhat.com O-Subject: Re: [RHEL-5.2 PATCH] BZ396831 Fix possible NULL pointer dereference inside of strncmp() if of_get_property() failed. (Oops possible). [rhel-5.2] Bugzilla: 396831 BZ#396831 https://bugzilla.redhat.com/show_bug.cgi?id=396831 Description: ============ This patch fixes possible NULL pointer dereference inside of strncmp() when of_get_property() fail to find the "model" property. Similar checks exist in sources for other ppc platforms, but missed for the case of IBM CHRP. Test status of the patch: ========================= Patched kernel was built without errors diff --git a/arch/powerpc/platforms/chrp/setup.c b/arch/powerpc/platforms/chrp/setup.c index 9c08ff3..f4def08 100644 --- a/arch/powerpc/platforms/chrp/setup.c +++ b/arch/powerpc/platforms/chrp/setup.c @@ -97,11 +97,15 @@ void chrp_show_cpuinfo(struct seq_file *m) int i, sdramen; unsigned int t; struct device_node *root; - const char *model = ""; + const char *model = NULL; root = find_path_device("/"); if (root) model = get_property(root, "model", NULL); + + if (!model) + model = ""; + seq_printf(m, "machine\t\t: CHRP %s\n", model); /* longtrail (goldengate) stuff */ @@ -191,10 +195,17 @@ static void __init sio_fixup_irq(const char *name, u8 device, u8 level, static void __init sio_init(void) { - struct device_node *root; + struct device_node *root = find_path_device("/"); + const char *model; + + if (!root) + return; + + model = get_property(root, model, NULL); + if (!model) + return; - if ((root = find_path_device("/")) && - !strncmp(get_property(root, "model", NULL), "IBM,LongTrail", 13)) { + if (!strncmp(model, "IBM,LongTrail", 13)) { /* logical device 0 (KBC/Keyboard) */ sio_fixup_irq("keyboard", 0, 1, 2); /* select logical device 1 (KBC/Mouse) */