| From bippy-7c5fe7eed585 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-2025-21949: LoongArch: Set hugetlb mmap base address aligned with pmd size |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| LoongArch: Set hugetlb mmap base address aligned with pmd size |
| |
| With ltp test case "testcases/bin/hugefork02", there is a dmesg error |
| report message such as: |
| |
| kernel BUG at mm/hugetlb.c:5550! |
| Oops - BUG[#1]: |
| CPU: 0 UID: 0 PID: 1517 Comm: hugefork02 Not tainted 6.14.0-rc2+ #241 |
| Hardware name: QEMU QEMU Virtual Machine, BIOS unknown 2/2/2022 |
| pc 90000000004eaf1c ra 9000000000485538 tp 900000010edbc000 sp 900000010edbf940 |
| a0 900000010edbfb00 a1 9000000108d20280 a2 00007fffe9474000 a3 00007ffff3474000 |
| a4 0000000000000000 a5 0000000000000003 a6 00000000003cadd3 a7 0000000000000000 |
| t0 0000000001ffffff t1 0000000001474000 t2 900000010ecd7900 t3 00007fffe9474000 |
| t4 00007fffe9474000 t5 0000000000000040 t6 900000010edbfb00 t7 0000000000000001 |
| t8 0000000000000005 u0 90000000004849d0 s9 900000010edbfa00 s0 9000000108d20280 |
| s1 00007fffe9474000 s2 0000000002000000 s3 9000000108d20280 s4 9000000002b38b10 |
| s5 900000010edbfb00 s6 00007ffff3474000 s7 0000000000000406 s8 900000010edbfa08 |
| ra: 9000000000485538 unmap_vmas+0x130/0x218 |
| ERA: 90000000004eaf1c __unmap_hugepage_range+0x6f4/0x7d0 |
| PRMD: 00000004 (PPLV0 +PIE -PWE) |
| EUEN: 00000007 (+FPE +SXE +ASXE -BTE) |
| ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) |
| ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) |
| PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) |
| Process hugefork02 (pid: 1517, threadinfo=00000000a670eaf4, task=000000007a95fc64) |
| Call Trace: |
| [<90000000004eaf1c>] __unmap_hugepage_range+0x6f4/0x7d0 |
| [<9000000000485534>] unmap_vmas+0x12c/0x218 |
| [<9000000000494068>] exit_mmap+0xe0/0x308 |
| [<900000000025fdc4>] mmput+0x74/0x180 |
| [<900000000026a284>] do_exit+0x294/0x898 |
| [<900000000026aa30>] do_group_exit+0x30/0x98 |
| [<900000000027bed4>] get_signal+0x83c/0x868 |
| [<90000000002457b4>] arch_do_signal_or_restart+0x54/0xfa0 |
| [<90000000015795e8>] irqentry_exit_to_user_mode+0xb8/0x138 |
| [<90000000002572d0>] tlb_do_page_fault_1+0x114/0x1b4 |
| |
| The problem is that base address allocated from hugetlbfs is not aligned |
| with pmd size. Here add a checking for hugetlbfs and align base address |
| with pmd size. After this patch the test case "testcases/bin/hugefork02" |
| passes to run. |
| |
| This is similar to the commit 7f24cbc9c4d42db8a3c8484d1 ("mm/mmap: teach |
| generic_get_unmapped_area{_topdown} to handle hugetlb mappings"). |
| |
| The Linux kernel CVE team has assigned CVE-2025-21949 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.19 with commit fa96b57c149061f71a70bd6582d995f6424fbbf4 and fixed in 6.13.7 with commit 242b34f48a377afe4b285b472bd0f17744fca8e8 |
| Issue introduced in 5.19 with commit fa96b57c149061f71a70bd6582d995f6424fbbf4 and fixed in 6.14 with commit 3109d5ff484b7bc7b955f166974c6776d91f247b |
| |
| 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-2025-21949 |
| 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: |
| arch/loongarch/mm/mmap.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/242b34f48a377afe4b285b472bd0f17744fca8e8 |
| https://git.kernel.org/stable/c/3109d5ff484b7bc7b955f166974c6776d91f247b |
