CVE-2024-42233

Sažetak

In the Linux kernel, the following vulnerability has been resolved: filemap: replace pte_offset_map() with pte_offset_map_nolock() The vmf->ptl in filemap_fault_recheck_pte_none() is still set from handle_pte_fault(). But at the same time, we did a pte_unmap(vmf->pte). After a pte_unmap(vmf->pte) unmap and rcu_read_unlock(), the page table may be racily changed and vmf->ptl maybe fails to protect the actual page table. Fix this by replacing pte_offset_map() with pte_offset_map_nolock(). As David said, the PTL pointer might be stale so if we continue to use it infilemap_fault_recheck_pte_none(), it might trigger UAF. Also, if the PTL fails, the issue fixed by commit 58f327f2ce80 ("filemap: avoid unnecessary major faults in filemap_fault()") might reappear.

Reference

CVSS

Base:	3.3
Impact:	1.4
Exploitability:	1.8

Pristup

Vektor	Složenost	Autentikacija
LOCAL	LOW	LOW

Impact

Povjerljivost	Cjelovitost	Dostupnost
NONE	LOW	NONE

CVSS vektor

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

Zadnje važnije ažuriranje

08-08-2024 - 14:56

Objavljeno

07-08-2024 - 16:15