Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > linux.kernel > #1247401

[PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially freed memory

Show all headers | View raw

Use 'of_property_read_u32()' instead of 'of_get_property()'+pointer
dereference in order to avoid access to potentially freed memory.

Use 'of_get_next_parent()' to simplify the while() loop and avoid the
need of a temp variable.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
---
v2: Use of_property_read_u32 instead of of_get_property+pointer dereference
*** Untested ***
---
 arch/powerpc/sysdev/mpc5xxx_clocks.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)

diff --git a/arch/powerpc/sysdev/mpc5xxx_clocks.c b/arch/powerpc/sysdev/mpc5xxx_clocks.c
index f4f0301..92fbcf8 100644
--- a/arch/powerpc/sysdev/mpc5xxx_clocks.c
+++ b/arch/powerpc/sysdev/mpc5xxx_clocks.c
@@ -13,21 +13,17 @@
 
 unsigned long mpc5xxx_get_bus_frequency(struct device_node *node)
 {
-	struct device_node *np;
-	const unsigned int *p_bus_freq = NULL;
+	u32 bus_freq = 0;
 
 	of_node_get(node);
 	while (node) {
-		p_bus_freq = of_get_property(node, "bus-frequency", NULL);
-		if (p_bus_freq)
+		if (!of_property_read_u32(node, "bus-frequency", &bus_freq))
 			break;
 
-		np = of_get_parent(node);
-		of_node_put(node);
-		node = np;
+		node = of_get_next_parent(node);
 	}
 	of_node_put(node);
 
-	return p_bus_freq ? *p_bus_freq : 0;
+	return bus_freq;
 }
 EXPORT_SYMBOL(mpc5xxx_get_bus_frequency);
-- 
2.1.4

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

Back to linux.kernel | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

[PATCH] powerpc/mpc5xxx: Use of_get_next_parent to simplify code Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-11 22:40 +0200
  Re: [PATCH] powerpc/mpc5xxx: Use of_get_next_parent to simplify  code Julia Lawall <julia.lawall@lip6.fr> - 2015-10-11 22:50 +0200
    Re: [PATCH] powerpc/mpc5xxx: Use of_get_next_parent to simplify code Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-12 07:10 +0200
  Re: powerpc/mpc5xxx: Use of_get_next_parent to simplify code Michael Ellerman <mpe@ellerman.id.au> - 2015-10-14 06:10 +0200
    [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially freed memory Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-15 08:00 +0200
      Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially  freed memory Michael Ellerman <mpe@ellerman.id.au> - 2015-10-15 08:40 +0200
        Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially freed  memory Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-16 08:30 +0200
          Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially  freed memory Gabriel Paubert <paubert@iram.es> - 2015-10-16 09:50 +0200
          Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially  freed memory Michael Ellerman <mpe@ellerman.id.au> - 2015-10-16 11:50 +0200
            Re: [PATCH v2] powerpc/mpc5xxx: Avoid dereferencing potentially freed  memory Christophe JAILLET <christophe.jaillet@wanadoo.fr> - 2015-10-16 22:10 +0200
  Re: powerpc/mpc5xxx: Use of_get_next_parent to simplify code Michael Ellerman <mpe@ellerman.id.au> - 2015-10-15 13:20 +0200

csiph-web