CVE-2024-26850

mm/debug_vm_pgtable: fix BUG_ON with pud advanced test

Description

In the Linux kernel, the following vulnerability has been resolved: mm/debug_vm_pgtable: fix BUG_ON with pud advanced test Architectures like powerpc add debug checks to ensure we find only devmap PUD pte entries. These debug checks are only done with CONFIG_DEBUG_VM. This patch marks the ptes used for PUD advanced test devmap pte entries so that we don't hit on debug checks on architecture like ppc64 as below. WARNING: CPU: 2 PID: 1 at arch/powerpc/mm/book3s64/radix_pgtable.c:1382 radix__pud_hugepage_update+0x38/0x138 .... NIP [c0000000000a7004] radix__pud_hugepage_update+0x38/0x138 LR [c0000000000a77a8] radix__pudp_huge_get_and_clear+0x28/0x60 Call Trace: [c000000004a2f950] [c000000004a2f9a0] 0xc000000004a2f9a0 (unreliable) [c000000004a2f980] [000d34c100000000] 0xd34c100000000 [c000000004a2f9a0] [c00000000206ba98] pud_advanced_tests+0x118/0x334 [c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48 [c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388 Also kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:202! .... NIP [c000000000096510] pudp_huge_get_and_clear_full+0x98/0x174 LR [c00000000206bb34] pud_advanced_tests+0x1b4/0x334 Call Trace: [c000000004a2f950] [000d34c100000000] 0xd34c100000000 (unreliable) [c000000004a2f9a0] [c00000000206bb34] pud_advanced_tests+0x1b4/0x334 [c000000004a2fa40] [c00000000206db34] debug_vm_pgtable+0xcbc/0x1c48 [c000000004a2fc10] [c00000000000fd28] do_one_initcall+0x60/0x388

5.5

CVSS

Severity: Medium

CVSS 3.1 •

EPSS 0.04%

Affected: Linux Linux

References

Link	Tags
https://git.kernel.org/stable/c/d2a9510c0e39d06f5544075c13040407bdbf2803	patch mailing list
https://git.kernel.org/stable/c/eeeddf85fc58d48c58ad916e4ca12363ebd8ab21	patch mailing list
https://git.kernel.org/stable/c/720da1e593b85a550593b415bf1d79a053133451	patch mailing list

Frequently Asked Questions

What is the severity of CVE-2024-26850?: CVE-2024-26850 has been scored as a medium severity vulnerability.
How to fix CVE-2024-26850?: To fix CVE-2024-26850, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2024-26850 being actively exploited in the wild?: As for now, there are no information to confirm that CVE-2024-26850 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2024-26850?: CVE-2024-26850 affects Linux Linux, Linux Linux.