of/overlay: put property on deadprops only after changeset add succeeds

Overview

In the Linux kernel, the following vulnerability has been resolved:

of/overlay: put property on deadprops only after changeset add succeeds

add_changeset_property() links a new property of a not-yet-live target node into the node's deadprops list before handing it to of_changeset_add_property(). If that fails, the error path frees the property but leaves the freed pointer linked in deadprops, and of_node_release() frees it a second time when the aborted overlay's node is released.

Record the changeset entry first and link the property into deadprops only on success. of_changeset_add_property() never looks at the node's property lists, so the order of the two steps is otherwise immaterial, and the error path frees a property that nothing references.

Affected

• Linux >= f96278810150fc39085d1872e5b39ea06366d03e < d5151496a0a2b19c9c0c7b0ebf86b3de55a8fa3a
• Linux >= f96278810150fc39085d1872e5b39ea06366d03e < 7dc6a769153c0457077a0da4888a00f61e66de15
• Linux >= f96278810150fc39085d1872e5b39ea06366d03e < 5857035a3b53a4e7b5a0d5a740189901ece0b079
• Linux >= f96278810150fc39085d1872e5b39ea06366d03e < 814f2da6995772c07a7c9c2cc6028b6e3f3ecc9c
• Linux b52ca352489be8beb7de3a8181509a0deaf72e21
• Linux >= 4.19.49 < 4.20
• Linux 5.0

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.