riscv: mm: Do not call pmd dtor on vmemmap page table teardown
The vmemmap's, which is used for RV64 with SPARSEMEM_VMEMMAP, page
tables are populated using pmd (page middle directory) hugetables.
However, the pmd allocation is not using the generic mechanism used by
the VMA code (e.g. pmd_alloc()), or the RISC-V specific
create_pgd_mapping()/alloc_pmd_late(). Instead, the vmemmap page table
code allocates a page, and calls vmemmap_set_pmd(). This results in
that the pmd ctor is *not* called, nor would it make sense to do so.
Now, when tearing down a vmemmap page table pmd, the cleanup code
would unconditionally, and incorrectly call the pmd dtor, which
results in a crash (best case).
This issue was found when running the HMM selftests:
| tools/testing/selftests/mm# ./test_hmm.sh smoke
| ... # when unloading the test_hmm.ko module
| page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10915b
| flags: 0x1000000000000000(node=0|zone=1)
| raw: 1000000000000000 0000000000000000 dead000000000122 0000000000000000
| raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
| page dumped because: VM_BUG_ON_PAGE(ptdesc->pmd_huge_pte)
| ------------[ cut here ]------------
| kernel BUG at include/linux/mm.h:3080!
| Kernel BUG [#1]
| Modules linked in: test_hmm(-) sch_fq_codel fuse drm drm_panel_orientation_quirks backlight dm_mod
| CPU: 1 UID: 0 PID: 514 Comm: modprobe Tainted: G W 6.12.0-00982-gf2a4f1682d07 #2
| Tainted: [W]=WARN
| Hardware name: riscv-virtio qemu/qemu, BIOS 2024.10 10/01/2024
| epc : remove_pgd_mapping+0xbec/0x1070
| ra : remove_pgd_mapping+0xbec/0x1070
| epc : ffffffff80010a68 ra : ffffffff80010a68 sp : ff20000000a73940
| gp : ffffffff827b2d88 tp : ff6000008785da40 t0 : ffffffff80fbce04
| t1 : 0720072007200720 t2 : 706d756420656761 s0 : ff20000000a73a50
| s1 : ff6000008915cff8 a0 : 0000000000000039 a1 : 0000000000000008
| a2 : ff600003fff0de20 a3 : 0000000000000000 a4 : 0000000000000000
| a5 : 0000000000000000 a6 : c0000000ffffefff a7 : ffffffff824469b8
| s2 : ff1c0000022456c0 s3 : ff1ffffffdbfffff s4 : ff6000008915c000
| s5 : ff6000008915c000 s6 : ff6000008915c000 s7 : ff1ffffffdc00000
| s8 : 0000000000000001 s9 : ff1ffffffdc00000 s10: ffffffff819a31f0
| s11: ffffffffffffffff t3 : ffffffff8000c950 t4 : ff60000080244f00
| t5 : ff60000080244000 t6 : ff20000000a73708
| status: 0000000200000120 badaddr: ffffffff80010a68 cause: 0000000000000003
| [<ffffffff80010a68>] remove_pgd_mapping+0xbec/0x1070
| [<ffffffff80fd238e>] vmemmap_free+0x14/0x1e
| [<ffffffff8032e698>] section_deactivate+0x220/0x452
| [<ffffffff8032ef7e>] sparse_remove_section+0x4a/0x58
| [<ffffffff802f8700>] __remove_pages+0x7e/0xba
| [<ffffffff803760d8>] memunmap_pages+0x2bc/0x3fe
| [<ffffffff02a3ca28>] dmirror_device_remove_chunks+0x2ea/0x518 [test_hmm]
| [<ffffffff02a3e026>] hmm_dmirror_exit+0x3e/0x1018 [test_hmm]
| [<ffffffff80102c14>] __riscv_sys_delete_module+0x15a/0x2a6
| [<ffffffff80fd020c>] do_trap_ecall_u+0x1f2/0x266
| [<ffffffff80fde0a2>] _new_vmalloc_restore_context_a0+0xc6/0xd2
| Code: bf51 7597 0184 8593 76a5 854a 4097 0029 80e7 2c00 (9002) 7597
| ---[ end trace 0000000000000000 ]---
| Kernel panic - not syncing: Fatal exception in interrupt
Add a check to avoid calling the pmd dtor, if the calling context is
vmemmap_free().
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
EUVD |
EUVD-2024-53321 | In the Linux kernel, the following vulnerability has been resolved: riscv: mm: Do not call pmd dtor on vmemmap page table teardown The vmemmap's, which is used for RV64 with SPARSEMEM_VMEMMAP, page tables are populated using pmd (page middle directory) hugetables. However, the pmd allocation is not using the generic mechanism used by the VMA code (e.g. pmd_alloc()), or the RISC-V specific create_pgd_mapping()/alloc_pmd_late(). Instead, the vmemmap page table code allocates a page, and calls vmemmap_set_pmd(). This results in that the pmd ctor is *not* called, nor would it make sense to do so. Now, when tearing down a vmemmap page table pmd, the cleanup code would unconditionally, and incorrectly call the pmd dtor, which results in a crash (best case). This issue was found when running the HMM selftests: | tools/testing/selftests/mm# ./test_hmm.sh smoke | ... # when unloading the test_hmm.ko module | page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10915b | flags: 0x1000000000000000(node=0|zone=1) | raw: 1000000000000000 0000000000000000 dead000000000122 0000000000000000 | raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 | page dumped because: VM_BUG_ON_PAGE(ptdesc->pmd_huge_pte) | ------------[ cut here ]------------ | kernel BUG at include/linux/mm.h:3080! | Kernel BUG [#1] | Modules linked in: test_hmm(-) sch_fq_codel fuse drm drm_panel_orientation_quirks backlight dm_mod | CPU: 1 UID: 0 PID: 514 Comm: modprobe Tainted: G W 6.12.0-00982-gf2a4f1682d07 #2 | Tainted: [W]=WARN | Hardware name: riscv-virtio qemu/qemu, BIOS 2024.10 10/01/2024 | epc : remove_pgd_mapping+0xbec/0x1070 | ra : remove_pgd_mapping+0xbec/0x1070 | epc : ffffffff80010a68 ra : ffffffff80010a68 sp : ff20000000a73940 | gp : ffffffff827b2d88 tp : ff6000008785da40 t0 : ffffffff80fbce04 | t1 : 0720072007200720 t2 : 706d756420656761 s0 : ff20000000a73a50 | s1 : ff6000008915cff8 a0 : 0000000000000039 a1 : 0000000000000008 | a2 : ff600003fff0de20 a3 : 0000000000000000 a4 : 0000000000000000 | a5 : 0000000000000000 a6 : c0000000ffffefff a7 : ffffffff824469b8 | s2 : ff1c0000022456c0 s3 : ff1ffffffdbfffff s4 : ff6000008915c000 | s5 : ff6000008915c000 s6 : ff6000008915c000 s7 : ff1ffffffdc00000 | s8 : 0000000000000001 s9 : ff1ffffffdc00000 s10: ffffffff819a31f0 | s11: ffffffffffffffff t3 : ffffffff8000c950 t4 : ff60000080244f00 | t5 : ff60000080244000 t6 : ff20000000a73708 | status: 0000000200000120 badaddr: ffffffff80010a68 cause: 0000000000000003 | [<ffffffff80010a68>] remove_pgd_mapping+0xbec/0x1070 | [<ffffffff80fd238e>] vmemmap_free+0x14/0x1e | [<ffffffff8032e698>] section_deactivate+0x220/0x452 | [<ffffffff8032ef7e>] sparse_remove_section+0x4a/0x58 | [<ffffffff802f8700>] __remove_pages+0x7e/0xba | [<ffffffff803760d8>] memunmap_pages+0x2bc/0x3fe | [<ffffffff02a3ca28>] dmirror_device_remove_chunks+0x2ea/0x518 [test_hmm] | [<ffffffff02a3e026>] hmm_dmirror_exit+0x3e/0x1018 [test_hmm] | [<ffffffff80102c14>] __riscv_sys_delete_module+0x15a/0x2a6 | [<ffffffff80fd020c>] do_trap_ecall_u+0x1f2/0x266 | [<ffffffff80fde0a2>] _new_vmalloc_restore_context_a0+0xc6/0xd2 | Code: bf51 7597 0184 8593 76a5 854a 4097 0029 80e7 2c00 (9002) 7597 | ---[ end trace 0000000000000000 ]--- | Kernel panic - not syncing: Fatal exception in interrupt Add a check to avoid calling the pmd dtor, if the calling context is vmemmap_free(). |
Ubuntu USN |
USN-7379-1 | Linux kernel vulnerabilities |
Ubuntu USN |
USN-7379-2 | Linux kernel (Raspberry Pi) vulnerabilities |
Ubuntu USN |
USN-7380-1 | Linux kernel (Low Latency) vulnerabilities |
Ubuntu USN |
USN-7381-1 | Linux kernel (Low Latency) vulnerabilities |
Ubuntu USN |
USN-7382-1 | Linux kernel (OEM) vulnerabilities |
Wed, 01 Oct 2025 21:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Thu, 13 Feb 2025 00:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-476 | |
| Metrics |
threat_severity
|
threat_severity
|
Mon, 06 Jan 2025 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Linux
Linux linux Kernel |
|
| Weaknesses | NVD-CWE-noinfo | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* |
|
| Vendors & Products |
Linux
Linux linux Kernel |
Mon, 30 Dec 2024 01:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Fri, 27 Dec 2024 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: riscv: mm: Do not call pmd dtor on vmemmap page table teardown The vmemmap's, which is used for RV64 with SPARSEMEM_VMEMMAP, page tables are populated using pmd (page middle directory) hugetables. However, the pmd allocation is not using the generic mechanism used by the VMA code (e.g. pmd_alloc()), or the RISC-V specific create_pgd_mapping()/alloc_pmd_late(). Instead, the vmemmap page table code allocates a page, and calls vmemmap_set_pmd(). This results in that the pmd ctor is *not* called, nor would it make sense to do so. Now, when tearing down a vmemmap page table pmd, the cleanup code would unconditionally, and incorrectly call the pmd dtor, which results in a crash (best case). This issue was found when running the HMM selftests: | tools/testing/selftests/mm# ./test_hmm.sh smoke | ... # when unloading the test_hmm.ko module | page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x10915b | flags: 0x1000000000000000(node=0|zone=1) | raw: 1000000000000000 0000000000000000 dead000000000122 0000000000000000 | raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000 | page dumped because: VM_BUG_ON_PAGE(ptdesc->pmd_huge_pte) | ------------[ cut here ]------------ | kernel BUG at include/linux/mm.h:3080! | Kernel BUG [#1] | Modules linked in: test_hmm(-) sch_fq_codel fuse drm drm_panel_orientation_quirks backlight dm_mod | CPU: 1 UID: 0 PID: 514 Comm: modprobe Tainted: G W 6.12.0-00982-gf2a4f1682d07 #2 | Tainted: [W]=WARN | Hardware name: riscv-virtio qemu/qemu, BIOS 2024.10 10/01/2024 | epc : remove_pgd_mapping+0xbec/0x1070 | ra : remove_pgd_mapping+0xbec/0x1070 | epc : ffffffff80010a68 ra : ffffffff80010a68 sp : ff20000000a73940 | gp : ffffffff827b2d88 tp : ff6000008785da40 t0 : ffffffff80fbce04 | t1 : 0720072007200720 t2 : 706d756420656761 s0 : ff20000000a73a50 | s1 : ff6000008915cff8 a0 : 0000000000000039 a1 : 0000000000000008 | a2 : ff600003fff0de20 a3 : 0000000000000000 a4 : 0000000000000000 | a5 : 0000000000000000 a6 : c0000000ffffefff a7 : ffffffff824469b8 | s2 : ff1c0000022456c0 s3 : ff1ffffffdbfffff s4 : ff6000008915c000 | s5 : ff6000008915c000 s6 : ff6000008915c000 s7 : ff1ffffffdc00000 | s8 : 0000000000000001 s9 : ff1ffffffdc00000 s10: ffffffff819a31f0 | s11: ffffffffffffffff t3 : ffffffff8000c950 t4 : ff60000080244f00 | t5 : ff60000080244000 t6 : ff20000000a73708 | status: 0000000200000120 badaddr: ffffffff80010a68 cause: 0000000000000003 | [<ffffffff80010a68>] remove_pgd_mapping+0xbec/0x1070 | [<ffffffff80fd238e>] vmemmap_free+0x14/0x1e | [<ffffffff8032e698>] section_deactivate+0x220/0x452 | [<ffffffff8032ef7e>] sparse_remove_section+0x4a/0x58 | [<ffffffff802f8700>] __remove_pages+0x7e/0xba | [<ffffffff803760d8>] memunmap_pages+0x2bc/0x3fe | [<ffffffff02a3ca28>] dmirror_device_remove_chunks+0x2ea/0x518 [test_hmm] | [<ffffffff02a3e026>] hmm_dmirror_exit+0x3e/0x1018 [test_hmm] | [<ffffffff80102c14>] __riscv_sys_delete_module+0x15a/0x2a6 | [<ffffffff80fd020c>] do_trap_ecall_u+0x1f2/0x266 | [<ffffffff80fde0a2>] _new_vmalloc_restore_context_a0+0xc6/0xd2 | Code: bf51 7597 0184 8593 76a5 854a 4097 0029 80e7 2c00 (9002) 7597 | ---[ end trace 0000000000000000 ]--- | Kernel panic - not syncing: Fatal exception in interrupt Add a check to avoid calling the pmd dtor, if the calling context is vmemmap_free(). | |
| Title | riscv: mm: Do not call pmd dtor on vmemmap page table teardown | |
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-05-11T20:57:02.938Z
Reserved: 2024-12-27T15:00:39.845Z
Link: CVE-2024-56673
Updated: 2025-10-01T15:46:04.278Z
Status : Modified
Published: 2024-12-27T15:15:27.210
Modified: 2025-10-01T20:17:39.740
Link: CVE-2024-56673
OpenCVE Enrichment
No data.
EUVD
Ubuntu USN