wifi: rt2x00: avoid full teardown before work setup in probe

Overview

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

wifi: rt2x00: avoid full teardown before work setup in probe

rt2x00lib_probe_dev() uses the full rt2x00lib_remove_dev() teardown for all probe failures. However, drv_data allocation and workqueue allocation can fail before intf_work, autowakeup_work and sleep_work have been initialized.

Do not enter the full remove path until the probe has reached the point where those work items are set up. Return directly for drv_data allocation failure, and use a small early cleanup path for workqueue allocation failure.

This issue was found by our static analysis tool and then confirmed by manual review of rt2x00lib_probe_dev() and rt2x00lib_remove_dev(). The early probe exits should not call a common teardown path that assumes the later work setup has already completed.

A QEMU PoC forced alloc_ordered_workqueue() to fail before the work initializers are reached. The resulting fail path entered rt2x00lib_remove_dev(), and DEBUG_OBJECTS reported invalid work drains with rt2x00lib_probe_dev() and rt2x00lib_remove_dev() in the stack.

Affected

• Linux >= 0439f5367c8d8bb2ebaca8d7329f51f3148b2fb2 < 8b58d1f1356df6a7d2de3f55bb665b18b04ffda0
• Linux >= 0439f5367c8d8bb2ebaca8d7329f51f3148b2fb2 < 59afe6148927395cf86f9429900e029a48b1d42b
• Linux >= 0439f5367c8d8bb2ebaca8d7329f51f3148b2fb2 < 3c0427d719bddb33caf18ff4ffb77cb47de7eb00
• Linux >= 0439f5367c8d8bb2ebaca8d7329f51f3148b2fb2 < eb7474d0253bb2de4793e1d3ce833e8564bbe732
• Linux >= 0439f5367c8d8bb2ebaca8d7329f51f3148b2fb2 < 66bd9b1a72de7c2f5141b02d796048aafaed8a49
• Linux >= 0439f5367c8d8bb2ebaca8d7329f51f3148b2fb2 < 816559409e340acaa5c9d868291dab30d8c80263
• Linux >= 0439f5367c8d8bb2ebaca8d7329f51f3148b2fb2 < 56994852d704535ea354a4627ca667b1b4fa0deb
• Linux >= 0439f5367c8d8bb2ebaca8d7329f51f3148b2fb2 < 536fb3d739d75a03cb318c0c6fe799425cfea501
• Linux 2.6.39

Remediation

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