Commit 7c867c88 authored Jan 24, 2011 by Jesper Juhl Committed by Jesse Barnes Feb 08, 2011

PCI: Avoid potential NULL pointer dereference in pci_scan_bridge



pci_add_new_bus() calls pci_alloc_child_bus() which calls pci_alloc_bus()
that allocates memory dynamically with kzalloc(). The return value of
kzalloc() is the pointer that's eventually returned from
pci_add_new_bus(), so since kzalloc() can fail and return NULL so can
pci_add_new_bus(). Thus we may end up dereferencing a NULL pointer in
drivers/pci/probe.c::pci_scan_bridge(). Seems to me we should test for
this and bail out if it happens rather than crashing.
Also removed some trailing whitespace that bugged me while looking at
this.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>

parent c13ff2ff

drivers/pci/probe.c

+3 −1

Original line number	Diff line number	Diff line
		@@ -764,6 +764,8 @@ int __devinit pci_scan_bridge(struct pci_bus bus, struct pci_dev dev, int max,
		if (pci_find_bus(pci_domain_nr(bus), max+1))
		goto out;
		child = pci_add_new_bus(bus, dev, ++max);
		if (!child)
		goto out;
		buses = (buses & 0xff000000)
		\| ((unsigned int)(child->primary) << 0)
		\| ((unsigned int)(child->secondary) << 8)

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