CVE-2025-39776
published 2025-09-11CVE-2025-39776: In the Linux kernel, the following vulnerability has been resolved: mm/debug_vm_pgtable: clear page table entries at destroy_args() The mm/debug_vm_pagetable…
high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
In the Linux kernel, the following vulnerability has been resolved:
mm/debug_vm_pgtable: clear page table entries at destroy_args()
The mm/debug_vm_pagetable test allocates manually page table entries for
the tests it runs, using also its manually allocated mm_struct. That in
itself is ok, but when it exits, at destroy_args() it fails to clear those
entries with the *_clear functions.
The problem is that leaves stale entries. If another process allocates an
mm_struct with a pgd at the same address, it may end up running into the
stale entry. This is happening in practice on a debug kernel with
CONFIG_DEBUG_VM_PGTABLE=y, for example this is the output with some extra
debugging I added (it prints a warning trace if pgtables_bytes goes
negative, in addition to the warning at check_mm() function):
[ 2.539353] debug_vm_pgtable: [get_random_vaddr ]: random_vaddr is 0x7ea247140000
[ 2.539366] kmem_cache info
[ 2.539374] kmem_cachep 0x000000002ce82385 - freelist 0x0000000000000000 - offset 0x508
[ 2.539447] debug_vm_pgtable: [init_args ]: args->mm is 0x000000002267cc9e
(...)
[ 2.552800] WARNING: CPU: 5 PID: 116 at include/linux/mm.h:2841 free_pud_range+0x8bc/0x8d0
[ 2.552816] Modules linked in:
[ 2.552843] CPU: 5 UID: 0 PID: 116 Comm: modprobe Not tainted 6.12.0-105.debug_vm2.el10.ppc64le+debug #1 VOLUNTARY
[ 2.552859] Hardware name: IBM,9009-41A POWER9 (architected) 0x4e0202 0xf000005 of:IBM,FW910.00 (VL910_062) hv:phyp pSeries
[ 2.552872] NIP: c0000000007eef3c LR: c0000000007eef30 CTR: c0000000003d8c90
[ 2.552885] REGS: c0000000622e73b0 TRAP: 0700 Not tainted (6.12.0-105.debug_vm2.el10.ppc64le+debug)
[ 2.552899] MSR: 800000000282b033 CR: 24002822 XER: 0000000a
[ 2.552954] CFAR: c0000000008f03f0 IRQMASK: 0
[ 2.552954] GPR00: c0000000007eef30 c0000000622e7650 c000000002b1ac00 0000000000000001
[ 2.552954] GPR04: 0000000000000008 0000000000000000 c0000000007eef30 ffffffffffffffff
[ 2.552954] GPR08: 00000000ffff00f5 0000000000000001 0000000000000048 0000000000004000
[ 2.55
Affected
32 ranges· showing 25
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| debian | debian_linux | — | — |
| debian | linux | < linux 6.1.153-1 (bookworm) | linux 6.1.153-1 (bookworm) |
| debian | linux-6.1 | < linux 6.1.153-1 (bookworm) | linux 6.1.153-1 (bookworm) |
| linux | linux | — | — |
| linux | linux | >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 7bf57a0709cd7c9088cea8de023d6f4fbf2518b0 | 7bf57a0709cd7c9088cea8de023d6f4fbf2518b0 |
| linux | linux | >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 47d2a149611b8a94d24add9868c442a4af278658 | 47d2a149611b8a94d24add9868c442a4af278658 |
| linux | linux | >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 63962ff932ef359925b94be2a88df6b4fd4fed0a | 63962ff932ef359925b94be2a88df6b4fd4fed0a |
| linux | linux | >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 61a9f2e5c49f05e3ea2c16674540a075a1b4be6f | 61a9f2e5c49f05e3ea2c16674540a075a1b4be6f |
| linux | linux | >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < 561171db3b3eb759ba3f284dba7a76f4476ade03 | 561171db3b3eb759ba3f284dba7a76f4476ade03 |
| linux | linux | >= 3c9b84f044a9e54cf56d1b2c9b80a2d2ce56d70a < dde30854bddfb5d69f30022b53c5955a41088b33 | dde30854bddfb5d69f30022b53c5955a41088b33 |
| linux | linux_kernel | — | — |
| linux | linux_kernel | >= 0 < 6.1.153-1 | 6.1.153-1 |
| linux | linux_kernel | >= 0 < 6.12.48-1 | 6.12.48-1 |
| linux | linux_kernel | >= 0 < 6.16.5-1 | 6.16.5-1 |
| linux | linux_kernel | >= 0 < 5.15.0-163.173 | 5.15.0-163.173 |
| linux | linux_kernel | >= 0 < 6.8.0-100.100 | 6.8.0-100.100 |
| linux | linux_kernel | >= 5.15 < 5.15.190 | 5.15.190 |
| linux | linux_kernel | >= 5.16 < 6.1.149 | 6.1.149 |
| linux | linux_kernel | >= 6.13 < 6.16.4 | 6.16.4 |
| linux | linux_kernel | >= 6.2 < 6.6.103 | 6.6.103 |
| linux | linux_kernel | >= 6.7 < 6.12.44 | 6.12.44 |
| msrc | azl3_kernel_6.6.96.2-2_on_azure_linux_3.0 | — | — |
| msrc | cbl2_kernel_5.15.186.1-1_on_cbl_mariner_2.0 | — | — |
| ubuntu | linux-aws | — | — |
| ubuntu | linux-aws-6.8 | — | — |
CVSS provenance
nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH