Bug 1227439 (CVE-2024-39477)

Summary:	VUL-0: CVE-2024-39477: kernel: mm/hugetlb: do not call vma_add_reservation upon ENOMEM
Product:	[Novell Products] SUSE Security Incidents	Reporter:	SMASH SMASH <smash_bz>
Component:	Incidents	Assignee:	Security Team bot <security-team>
Status:	RESOLVED FIXED	QA Contact:	Security Team bot <security-team>
Severity:	Normal
Priority:	P3 - Medium	CC:	andrea.mattiazzo, jlee
Version:	unspecified
Target Milestone:	---
Hardware:	Other
OS:	Other
URL:	https://smash.suse.de/issue/412897/
Whiteboard:	CVSSv3.1:SUSE:CVE-2024-39477:5.5:(AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Found By:	Security Response Team	Services Priority:
Business Priority:		Blocker:	---
Marketing QA Status:	---	IT Deployment:	---

Description SMASH SMASH 2024-07-05 09:56:03 UTC

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

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2024-39477
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2024/CVE-2024-39477.mbox
https://git.kernel.org/stable/c/aa998f9dcb34c28448f86e8f5490f20d5eb0eac7
https://git.kernel.org/stable/c/8daf9c702ee7f825f0de8600abff764acfedea13
https://www.cve.org/CVERecord?id=CVE-2024-39477

Comment 2 Andrea Mattiazzo 2024-07-08 09:16:05 UTC

All done, closing.