[PATCH 3.12 068/142] MIPS: GIC: Prevent array overrun

From: Jiri Slaby
Date: Fri Sep 26 2014 - 06:16:36 EST


From: Jeffrey Deans <jeffrey.deans@xxxxxxxxxx>

3.12-stable review patch. If anyone has any objections, please let me know.

===============

commit ffc8415afab20bd97754efae6aad1f67b531132b upstream.

A GIC interrupt which is declared as having a GIC_MAP_TO_NMI_MSK
mapping causes the cpu parameter to gic_setup_intr() to be increased
to 32, causing memory corruption when pcpu_masks[] is written to again
later in the function.

Signed-off-by: Jeffrey Deans <jeffrey.deans@xxxxxxxxxx>
Signed-off-by: Markos Chandras <markos.chandras@xxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Patchwork: https://patchwork.linux-mips.org/patch/7375/
Signed-off-by: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Signed-off-by: Jiri Slaby <jslaby@xxxxxxx>
---
arch/mips/kernel/irq-gic.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/arch/mips/kernel/irq-gic.c b/arch/mips/kernel/irq-gic.c
index 5b5ddb231f26..78f18436cdf2 100644
--- a/arch/mips/kernel/irq-gic.c
+++ b/arch/mips/kernel/irq-gic.c
@@ -255,11 +255,13 @@ static void __init gic_setup_intr(unsigned int intr, unsigned int cpu,

/* Setup Intr to Pin mapping */
if (pin & GIC_MAP_TO_NMI_MSK) {
+ int i;
+
GICWRITE(GIC_REG_ADDR(SHARED, GIC_SH_MAP_TO_PIN(intr)), pin);
/* FIXME: hack to route NMI to all cpu's */
- for (cpu = 0; cpu < NR_CPUS; cpu += 32) {
+ for (i = 0; i < NR_CPUS; i += 32) {
GICWRITE(GIC_REG_ADDR(SHARED,
- GIC_SH_MAP_TO_VPE_REG_OFF(intr, cpu)),
+ GIC_SH_MAP_TO_VPE_REG_OFF(intr, i)),
0xffffffff);
}
} else {
--
2.1.0

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