Bug 2320628 (CVE-2024-50061)

Summary: CVE-2024-50061 kernel: i3c: master: cdns: Fix use after free vulnerability in cdns_i3c_master Driver Due to Race Condition
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
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Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
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Hardware: All   
OS: Linux   
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Bug Depends On: 2320886    
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Description OSIDB Bzimport 2024-10-21 20:04:34 UTC
In the Linux kernel, the following vulnerability has been resolved:

i3c: master: cdns: Fix use after free vulnerability in cdns_i3c_master Driver Due to Race Condition

In the cdns_i3c_master_probe function, &master->hj_work is bound with
cdns_i3c_master_hj. And cdns_i3c_master_interrupt can call
cnds_i3c_master_demux_ibis function to start the work.

If we remove the module which will call cdns_i3c_master_remove to
make cleanup, it will free master->base through i3c_master_unregister
while the work mentioned above will be used. The sequence of operations
that may lead to a UAF bug is as follows:

CPU0                                      CPU1

                                     | cdns_i3c_master_hj
cdns_i3c_master_remove               |
i3c_master_unregister(&master->base) |
device_unregister(&master->dev)      |
device_release                       |
//free master->base                  |
                                     | i3c_master_do_daa(&master->base)
                                     | //use master->base

Fix it by ensuring that the work is canceled before proceeding with
the cleanup in cdns_i3c_master_remove.

Comment 1 Avinash Hanwate 2024-10-22 09:41:52 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102136-CVE-2024-50061-50ab@gregkh/T