CVE-2024-26850: mm/debug_vm_pgtable: fix BUG_ON with pud advanced test
In the Linux kernel, the following vulnerability has been resolved:
mm/debugvmpgtable: fix BUGON 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 CONFIGDEBUGVM. 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/radixpgtable.c:1382 radixpudhugepageupdate+0x38/0x138 .... NIP [c0000000000a7004] radixpudhugepageupdate+0x38/0x138 LR [c0000000000a77a8] radixpudphugegetandclear+0x28/0x60 Call Trace: [c000000004a2f950] [c000000004a2f9a0] 0xc000000004a2f9a0 (unreliable) [c000000004a2f980] [000d34c100000000] 0xd34c100000000 [c000000004a2f9a0] [c00000000206ba98] pudadvancedtests+0x118/0x334 [c000000004a2fa40] [c00000000206db34] debugvmpgtable+0xcbc/0x1c48 [c000000004a2fc10] [c00000000000fd28] dooneinitcall+0x60/0x388
Also
kernel BUG at arch/powerpc/mm/book3s64/pgtable.c:202! ....
NIP [c000000000096510] pudphugegetandclearfull+0x98/0x174 LR [c00000000206bb34] pudadvancedtests+0x1b4/0x334 Call Trace: [c000000004a2f950] [000d34c100000000] 0xd34c100000000 (unreliable) [c000000004a2f9a0] [c00000000206bb34] pudadvancedtests+0x1b4/0x334 [c000000004a2fa40] [c00000000206db34] debugvmpgtable+0xcbc/0x1c48 [c000000004a2fc10] [c00000000000fd28] dooneinitcall+0x60/0x388
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2024-26850?
CVE-2024-26850 has a medium severity rating due to its impact on the Linux kernel's functionality.
How do I fix CVE-2024-26850?
To fix CVE-2024-26850, update your Linux kernel to the patched version provided by your distribution.
Which versions of the Linux kernel are affected by CVE-2024-26850?
CVE-2024-26850 affects specific versions of the Linux kernel where CONFIG_DEBUG_VM is enabled.
What systems are at risk due to CVE-2024-26850?
Systems running the affected versions of the Linux kernel on architectures like powerpc are at risk.
What is the nature of the issue in CVE-2024-26850?
CVE-2024-26850 involves a BUG_ON condition triggered by debug checks in the memory management of the Linux kernel.