In the Linux kernel, the following vulnerability has been resolved:
kasan: avoid sleepable page allocation from atomic context
apply_to_pte_range() enters the lazy MMU mode and then invokes kasan_populate_vmalloc_pte() callback on each page table walk iteration. However, the callback can go into sleep when trying to allocate a single page, e.g. if an architecutre disables preemption on lazy MMU mode enter.
On s390 if make arch_enter_lazy_mmu_mode() -> preempt_enable() and arch_leave_lazy_mmu_mode() -> preempt_disable(), such crash occurs:
[ 0.663336] BUG: sleeping function called from invalid context at ./include/linux/sched/mm.h:321 [ 0.663348] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 2, name: kthreadd [ 0.663358] preempt_count: 1, expected: 0 [ 0.663366] RCU nest depth: 0, expected: 0 [ 0.663375] no locks held by kthreadd/2. [ 0.663383] Preemption disabled at: [ 0.663386] [<0002f3284cbb4eda>] apply_to_pte_range+0xfa/0x4a0 [ 0.663405] CPU: 0 UID: 0 PID: 2 Comm: kthreadd Not tainted 6.15.0-rc5-gcc-kasan-00043-gd76bb1ebb558-dirty #162 PREEMPT [ 0.663408] Hardware name: IBM 3931 A01 701 (KVM/Linux) [ 0.663409] Call Trace: [ 0.663410] [<0002f3284c385f58>] dump_stack_lvl+0xe8/0x140 [ 0.663413] [<0002f3284c507b9e>] __might_resched+0x66e/0x700 [ 0.663415] [<0002f3284cc4f6c0>] __alloc_frozen_pages_noprof+0x370/0x4b0 [ 0.663419] [<0002f3284ccc73c0>] alloc_pages_mpol+0x1a0/0x4a0 [ 0.663421] [<0002f3284ccc8518>] alloc_frozen_pages_noprof+0x88/0xc0 [ 0.663424] [<0002f3284ccc8572>] alloc_pages_noprof+0x22/0x120 [ 0.663427] [<0002f3284cc341ac>] get_free_pages_noprof+0x2c/0xc0 [ 0.663429] [<0002f3284cceba70>] kasan_populate_vmalloc_pte+0x50/0x120 [ 0.663433] [<0002f3284cbb4ef8>] apply_to_pte_range+0x118/0x4a0 [ 0.663435] [<0002f3284cbc7c14>] apply_to_pmd_range+0x194/0x3e0 [ 0.663437] [<0002f3284cbc99be>] __apply_to_page_range+0x2fe/0x7a0 [ 0.663440] [<0002f3284cbc9e88>] apply_to_page_range+0x28/0x40 [ 0.663442] [<0002f3284ccebf12>] kasan_populate_vmalloc+0x82/0xa0 [ 0.663445] [<0002f3284cc1578c>] alloc_vmap_area+0x34c/0xc10 [ 0.663448] [<0002f3284cc1c2a6>] __get_vm_area_node+0x186/0x2a0 [ 0.663451] [<0002f3284cc1e696>] __vmalloc_node_range_noprof+0x116/0x310 [ 0.663454] [<0002f3284cc1d950>] __vmalloc_node_noprof+0xd0/0x110 [ 0.663457] [<0002f3284c454b88>] alloc_thread_stack_node+0xf8/0x330 [ 0.663460] [<0002f3284c458d56>] dup_task_struct+0x66/0x4d0 [ 0.663463] [<0002f3284c45be90>] copy_process+0x280/0x4b90 [ 0.663465] [<0002f3284c460940>] kernel_clone+0xd0/0x4b0 [ 0.663467] [<0002f3284c46115e>] kernel_thread+0xbe/0xe0 [ 0.663469] [<0002f3284c4e440e>] kthreadd+0x50e/0x7f0 [ 0.663472] [<0002f3284c38c04a>] __ret_from_fork+0x8a/0xf0 [ 0.663475] [<0002f3284ed57ff2>] ret_from_fork+0xa/0x38
Instead of allocating single pages per-PTE, bulk-allocate the shadow memory prior to applying kasan_populate_vmalloc_pte() callback on a page range.
CVSS Details
- CVSS 3.1 Base Score: 5.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Debian | — | No solution exists | Jun 20, 2025 | Jun 18, 2025 |
| Redhat_linux | — | No solution exists | Jul 9, 2025 | Jun 18, 2025 |
| Ubuntu | — | Upgrade linux-image-6.14.0-32-generic-64kUpgrade linux-image-virtual-hwe-24.04Upgrade linux-image-6.14.0-1012-oemUpgrade linux-image-oem-6.14Upgrade linux-image-gcpUpgrade linux-image-6.14.0-1013-oracleUpgrade linux-image-oem-24.04bUpgrade linux-image-azure-6.14Upgrade linux-image-6.14.0-1012-azureUpgrade linux-image-6.14.0-1012-realtimeUpgrade linux-image-raspi-6.14Upgrade linux-image-6.14.0-1016-gcp-64kUpgrade linux-image-genericUpgrade linux-image-generic-64kUpgrade linux-image-oem-24.04aUpgrade linux-image-oracle-64k-6.14Upgrade linux-image-realtime-hwe-24.04Upgrade linux-image-virtualUpgrade linux-image-generic-64k-6.14Upgrade linux-image-virtual-6.14Upgrade linux-image-6.14.0-1014-raspiUpgrade linux-image-oracleUpgrade linux-image-awsUpgrade linux-image-gcp-6.14Upgrade linux-image-aws-64k-6.14Upgrade linux-image-6.14.0-1013-aws-64kUpgrade linux-image-6.14.0-32-genericUpgrade linux-image-generic-hwe-24.04Upgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-realtimeUpgrade linux-image-aws-6.14Upgrade linux-image-raspiUpgrade linux-image-6.14.0-1016-gcpUpgrade linux-image-oracle-6.14Upgrade linux-image-oem-24.04cUpgrade linux-image-oem-24.04Upgrade linux-image-gcp-64kUpgrade linux-image-6.14.0-1013-awsUpgrade linux-image-realtime-6.14Upgrade linux-image-oracle-64kUpgrade linux-image-generic-6.14Upgrade linux-image-azureUpgrade linux-image-6.14.0-1013-oracle-64kUpgrade linux-image-gcp-64k-6.14Upgrade linux-image-aws-64k | Jun 26, 2025 | Jun 18, 2025 |
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