[PATCH 3.19.y-ckt 077/128] PCI: Prevent out of bounds access in numa_node override

From: Kamal Mostafa
Date: Wed Dec 16 2015 - 12:40:44 EST


3.19.8-ckt12 -stable review patch. If anyone has any objections, please let me know.

------------------

From: Mathias Krause <minipli@xxxxxxxxxxxxxx>

commit 3dcc8d39cf15fa3ceabedcffcbd3958fe953555a upstream.

Commit 1266963170f5 ("PCI: Prevent out of bounds access in numa_node
override") missed that the user-provided node could also be negative.
Handle this case as well to avoid out-of-bounds accesses to the
node_states[] array. However, allow the special value -1, i.e.
NUMA_NO_NODE, to be able to set the 'no specific node' configuration.

Fixes: 1266963170f5 ("PCI: Prevent out of bounds access in numa_node override")
Fixes: 63692df103e9 ("PCI: Allow numa_node override via sysfs")
Signed-off-by: Mathias Krause <minipli@xxxxxxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
CC: Sasha Levin <sasha.levin@xxxxxxxxxx>
CC: Prarit Bhargava <prarit@xxxxxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/pci/pci-sysfs.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 9261868..eead54c 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -216,7 +216,10 @@ static ssize_t numa_node_store(struct device *dev,
if (ret)
return ret;

- if (node >= MAX_NUMNODES || !node_online(node))
+ if ((node < 0 && node != NUMA_NO_NODE) || node >= MAX_NUMNODES)
+ return -EINVAL;
+
+ if (node != NUMA_NO_NODE && !node_online(node))
return -EINVAL;

add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
--
1.9.1

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