Bug 2309837 (CVE-2024-44974)

Summary: CVE-2024-44974 kernel: mptcp: pm: avoid possible UaF when selecting endp
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
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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: 2309944    
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Description OSIDB Bzimport 2024-09-04 20:21:17 UTC 
In the Linux kernel, the following vulnerability has been resolved:

mptcp: pm: avoid possible UaF when selecting endp

select_local_address() and select_signal_address() both select an
endpoint entry from the list inside an RCU protected section, but return
a reference to it, to be read later on. If the entry is dereferenced
after the RCU unlock, reading info could cause a Use-after-Free.

A simple solution is to copy the required info while inside the RCU
protected section to avoid any risk of UaF later. The address ID might
need to be modified later to handle the ID0 case later, so a copy seems
OK to deal with.
Comment 1 Robb Gatica 2024-09-04 22:16:59 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024090440-CVE-2024-44974-dbe8@gregkh/T