Fix crash caused by spurious aliases phandles. #161
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If a device tree has specified a phandle for an aliases node, perhaps appearing as "aliases: aliases" in the device tree source, the phandle property will occur in the device tree data for the node. If this property value is not decoded appropriately by prop_value, fdt_scan_node will raise a TypeError trying to use the inappropriately decoded value as a dictionary key when recording a phandle-to-node association. This effectively crashes the tool. This modification lets prop_value decode property values normally instead of treating aliases nodes as a special case. Any phandle associated with such a node will then be reported by the validator in a message of the following form: aliases: phandle: 26 is not of type 'array' This is somewhat opaque and could arguably be reported in a more helpful way, but it indicates the presence of the spurious phandle instead of terminating abruptly. Signed-off-by: Paul Boddie <paul@boddie.org.uk>
robherring
requested changes
Apr 22, 2025
| @@ -82,7 +82,7 @@ def prop_value(validator, nodename, p): | |||
| data = bytes(p) | |||
| fmt = None | |||
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| if nodename in {'__fixups__', 'aliases'}: | |||
| if nodename in {'__fixups__'}: | |||
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This is going to result in aliases property names possibly matching on some actual property name and getting the type wrong. You need to add an exclusion for 'phandle' (and perhaps 'linux,phandle' for completeness).
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I suppose that it might then be easier to preserve the special case for 'aliases' and to test p.name for 'phandle', decoding the numeric data obtained for that property. This would cover the case of a phandle having been introduced without risking other breakage.
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If a device tree has specified a phandle for an aliases node, perhaps appearing as "aliases: aliases" in the device tree source, the phandle property will occur in the device tree data for the node.
If this property value is not decoded appropriately by prop_value, fdt_scan_node will raise a TypeError trying to use the inappropriately decoded value as a dictionary key when recording a phandle-to-node association. This effectively crashes the tool.
This modification lets prop_value decode property values normally instead of treating aliases nodes as a special case. Any phandle associated with such a node will then be reported by the validator in a message of the following form:
aliases: phandle: 26 is not of type 'array'
This is somewhat opaque and could arguably be reported in a more helpful way, but it indicates the presence of the spurious phandle instead of terminating abruptly.