In the Linux kernel, the following vulnerability has been resolved:
udmabuf: change folios array from kmalloc to kvmalloc
When PAGE_SIZE 4096, MAX_PAGE_ORDER 10, 64bit machine, page_alloc only support 4MB. If above this, trigger this warn and return NULL.
udmabuf can change size limit, if change it to 3072(3GB), and then alloc 3GB udmabuf, will fail create.
[ 4080.876581] ------------[ cut here ]------------ [ 4080.876843] WARNING: CPU: 3 PID: 2015 at mm/page_alloc.c:4556 __alloc_pages+0x2c8/0x350 [ 4080.878839] RIP: 0010:__alloc_pages+0x2c8/0x350 [ 4080.879470] Call Trace: [ 4080.879473] <TASK> [ 4080.879473] ? __alloc_pages+0x2c8/0x350 [ 4080.879475] ? __warn.cold+0x8e/0xe8 [ 4080.880647] ? __alloc_pages+0x2c8/0x350 [ 4080.880909] ? report_bug+0xff/0x140 [ 4080.881175] ? handle_bug+0x3c/0x80 [ 4080.881556] ? exc_invalid_op+0x17/0x70 [ 4080.881559] ? asm_exc_invalid_op+0x1a/0x20 [ 4080.882077] ? udmabuf_create+0x131/0x400
Because MAX_PAGE_ORDER, kmalloc can max alloc 4096 * (1 << 10), 4MB memory, each array entry is pointer(8byte), so can save 524288 pages(2GB).
Further more, costly order(order 3) may not be guaranteed that it can be applied for, due to fragmentation.
This patch change udmabuf array use kvmalloc_array, this can fallback alloc into vmalloc, which can guarantee allocation for any size and does not affect the performance of kmalloc allocations.
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 existsUpgrade linux | May 15, 2025 | Dec 27, 2024 |
| Redhat_linux | — | Upgrade kernelUpgrade kernel-rtNo solution exists | Jul 9, 2025 | Dec 27, 2024 |
| Ubuntu | — | Upgrade linux-image-generic-64kUpgrade linux-image-6.11.0-18-genericUpgrade linux-image-oem-24.04Upgrade linux-image-raspiUpgrade linux-image-6.11.0-1009-azure-fdeUpgrade linux-image-realtime-hwe-24.04Upgrade linux-image-virtual-hwe-24.04Upgrade linux-image-oem-24.04aUpgrade linux-image-azureUpgrade linux-image-6.11.0-1010-lowlatencyUpgrade linux-image-6.11.0-1015-oemUpgrade linux-image-6.11.0-18-generic-64kUpgrade linux-image-6.11.0-1009-azureUpgrade linux-image-gcpUpgrade linux-image-oracle-64kUpgrade linux-image-6.11.0-1009-awsUpgrade linux-image-6.11.0-1011-oracleUpgrade linux-image-generic-hwe-24.04Upgrade linux-image-6.11.0-1010-lowlatency-64kUpgrade linux-image-6.11.0-1009-gcpUpgrade linux-image-6.11.0-1008-raspiUpgrade linux-image-6.11.0-1011-oracle-64kUpgrade linux-image-6.11.0-1005-realtimeUpgrade linux-image-lowlatencyUpgrade linux-image-lowlatency-64kUpgrade linux-image-awsUpgrade linux-image-virtualUpgrade linux-image-genericUpgrade linux-image-generic-64k-hwe-24.04Upgrade linux-image-realtimeUpgrade linux-image-oracleUpgrade linux-image-oem-24.04bUpgrade linux-image-azure-fde | Feb 20, 2025 | Dec 27, 2024 |
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