Vulnerability Details CVE-2024-42293
In the Linux kernel, the following vulnerability has been resolved:
arm64: mm: Fix lockless walks with static and dynamic page-table folding
Lina reports random oopsen originating from the fast GUP code when
16K pages are used with 4-level page-tables, the fourth level being
folded at runtime due to lack of LPA2.
In this configuration, the generic implementation of
p4d_offset_lockless() will return a 'p4d_t *' corresponding to the
'pgd_t' allocated on the stack of the caller, gup_fast_pgd_range().
This is normally fine, but when the fourth level of page-table is folded
at runtime, pud_offset_lockless() will offset from the address of the
'p4d_t' to calculate the address of the PUD in the same page-table page.
This results in a stray stack read when the 'p4d_t' has been allocated
on the stack and can send the walker into the weeds.
Fix the problem by providing our own definition of p4d_offset_lockless()
when CONFIG_PGTABLE_LEVELS <= 4 which returns the real page-table
pointer rather than the address of the local stack variable.
Exploit prediction scoring system (EPSS) score
EPSS Score 0.001
EPSS Ranking 15.9%
CVSS Severity
CVSS v3 Score 5.5
References
Products affected by CVE-2024-42293
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cpe:2.3:o:linux:linux_kernel:6.10
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cpe:2.3:o:linux:linux_kernel:6.10.0
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cpe:2.3:o:linux:linux_kernel:6.10.1
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cpe:2.3:o:linux:linux_kernel:6.10.2
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cpe:2.3:o:linux:linux_kernel:6.9
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cpe:2.3:o:linux:linux_kernel:6.9.1
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cpe:2.3:o:linux:linux_kernel:6.9.10
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cpe:2.3:o:linux:linux_kernel:6.9.11
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cpe:2.3:o:linux:linux_kernel:6.9.12
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cpe:2.3:o:linux:linux_kernel:6.9.2
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cpe:2.3:o:linux:linux_kernel:6.9.3
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cpe:2.3:o:linux:linux_kernel:6.9.4
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cpe:2.3:o:linux:linux_kernel:6.9.5
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cpe:2.3:o:linux:linux_kernel:6.9.6
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cpe:2.3:o:linux:linux_kernel:6.9.7
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cpe:2.3:o:linux:linux_kernel:6.9.8
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cpe:2.3:o:linux:linux_kernel:6.9.9