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of: address: Unify resource bounds overflow checking

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The members "start" and "end" of struct resource are of type
"resource_size_t" which can be 32bit wide.
Values read from OF however are always 64bit wide.

Refactor the diff overflow checks into a helper function.
Also extend the checks to validate each calculation step.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Link: https://lore.kernel.org/r/20240906-of-address-overflow-v1-1-19567aaa61da@linutronix.de
[robh: Fix to not return error on 0 sized resource]
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
This commit is contained in:
Thomas Weißschuh 2024-09-06 14:25:19 +02:00 committed by Rob Herring (Arm)
parent 22e2bf1214
commit 1a52a094c2
1 changed files with 24 additions and 19 deletions
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43
drivers/of/address.c
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@ -198,6 +198,23 @@ static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
#endif /* CONFIG_PCI */
static int __of_address_resource_bounds(struct resource *r, u64 start, u64 size)
{
u64 end = start;
if (overflows_type(start, r->start))
return -EOVERFLOW;
if (size && check_add_overflow(end, size - 1, &end))
return -EOVERFLOW;
if (overflows_type(end, r->end))
return -EOVERFLOW;
r->start = start;
r->end = end;
return 0;
}
/*
* of_pci_range_to_resource - Create a resource from an of_pci_range
* @range: the PCI range that describes the resource
@ -216,6 +233,7 @@ static u64 of_bus_pci_map(__be32 *addr, const __be32 *range, int na, int ns,
int of_pci_range_to_resource(struct of_pci_range *range,
struct device_node *np, struct resource *res)
{
u64 start;
int err;
res->flags = range->flags;
res->parent = res->child = res->sibling = NULL;
@ -232,18 +250,11 @@ int of_pci_range_to_resource(struct of_pci_range *range,
err = -EINVAL;
goto invalid_range;
}
res->start = port;
start = port;
} else {
if ((sizeof(resource_size_t) < 8) &&
upper_32_bits(range->cpu_addr)) {
err = -EINVAL;
goto invalid_range;
}
res->start = range->cpu_addr;
start = range->cpu_addr;
}
res->end = res->start + range->size - 1;
return 0;
return __of_address_resource_bounds(res, start, range->size);
invalid_range:
res->start = (resource_size_t)OF_BAD_ADDR;
@ -259,8 +270,8 @@ EXPORT_SYMBOL(of_pci_range_to_resource);
* @res: pointer to a valid resource that will be updated to
* reflect the values contained in the range.
*
* Returns ENOENT if the entry is not found or EINVAL if the range cannot be
* converted to resource.
* Returns -ENOENT if the entry is not found or -EOVERFLOW if the range
* cannot be converted to resource.
*/
int of_range_to_resource(struct device_node *np, int index, struct resource *res)
{
@ -1062,16 +1073,10 @@ static int __of_address_to_resource(struct device_node *dev, int index, int bar_
if (of_mmio_is_nonposted(dev))
flags |= IORESOURCE_MEM_NONPOSTED;
if (overflows_type(taddr, r->start))
return -EOVERFLOW;
r->start = taddr;
if (overflows_type(taddr + size - 1, r->end))
return -EOVERFLOW;
r->end = taddr + size - 1;
r->flags = flags;
r->name = name ? name : dev->full_name;
return 0;
return __of_address_resource_bounds(r, taddr, size);
}
/**