| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: 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 |
| |
| The Linux kernel CVE team has assigned CVE-2024-26850 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.6 with commit 27af67f35631ac4b61b5e4455b44c9aee8d2cc4b and fixed in 6.6.21 with commit d2a9510c0e39d06f5544075c13040407bdbf2803 |
| Issue introduced in 6.6 with commit 27af67f35631ac4b61b5e4455b44c9aee8d2cc4b and fixed in 6.7.9 with commit eeeddf85fc58d48c58ad916e4ca12363ebd8ab21 |
| Issue introduced in 6.6 with commit 27af67f35631ac4b61b5e4455b44c9aee8d2cc4b and fixed in 6.8 with commit 720da1e593b85a550593b415bf1d79a053133451 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2024-26850 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| mm/debug_vm_pgtable.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/d2a9510c0e39d06f5544075c13040407bdbf2803 |
| https://git.kernel.org/stable/c/eeeddf85fc58d48c58ad916e4ca12363ebd8ab21 |
| https://git.kernel.org/stable/c/720da1e593b85a550593b415bf1d79a053133451 |
