Bug 2320175 (CVE-2024-47676)

Summary: CVE-2024-47676 kernel: mm/hugetlb.c: fix UAF of vma in hugetlb fault pathway
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: 2320307    
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Description OSIDB Bzimport 2024-10-21 12:01:41 UTC 
In the Linux kernel, the following vulnerability has been resolved:

mm/hugetlb.c: fix UAF of vma in hugetlb fault pathway

Syzbot reports a UAF in hugetlb_fault().  This happens because
vmf_anon_prepare() could drop the per-VMA lock and allow the current VMA
to be freed before hugetlb_vma_unlock_read() is called.

We can fix this by using a modified version of vmf_anon_prepare() that
doesn't release the VMA lock on failure, and then release it ourselves
after hugetlb_vma_unlock_read().
Comment 1 Michal Findra 2024-10-21 14:03:50 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102105-CVE-2024-47676-016b@gregkh/T