CVE-2024-39477 Information

Jul 06, 2024 cve

Description

In the Linux kernel the following vulnerability has been resolved:

mm/hugetlb: do not call vma_add_reservation upon ENOMEM

sysbot reported a splat [1] on __unmap_hugepage_range(). This is because vma_needs_reservation() can return -ENOMEM if allocate_file_region_entries() fails to allocate the file_region struct for the reservation.

Check for that and do not call vma_add_reservation() if that is the case otherwise region_abort() and region_del() will see that we do not have any file_regions.

If we detect that vma_needs_reservation() returned -ENOMEM we clear the hugetlb_restore_reserve flag as if this reservation was still consumed so free_huge_folio() will not increment the resv count.

[1] https://lore.kernel.org/linux-mm/0000000000004096100617c58d54@google.com/T/ma5983bc1ab18a54910da83416b3f89f3c7ee43aa

Reference

https://git.kernel.org/stable/c/aa998f9dcb34c28448f86e8f5490f20d5eb0eac7 https://git.kernel.org/stable/c/8daf9c702ee7f825f0de8600abff764acfedea13

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