Vulnerability · Published Jul 9, 2025 · Assigned by Linux
CVE-2025-38256io_uring/rsrc: fix folio unpinning
Medium 5.5
In plain English
A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 6% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
In the Linux kernel, the following vulnerability has been resolved: io_uring/rsrc: fix folio unpinning syzbot complains about an unmapping failure: [ 108.070381][ T14] kernel BUG at mm/gup.c:71! [ 108.070502][ T14] Internal error: Oops - BUG: 00000000f2000800 [#1] SMP [ 108.123672][ T14] Hardware name: QEMU KVM Virtual Machine, BIOS edk2-20250221-8.fc42 02/21/2025 [ 108.127458][ T14] Workqueue: iou_exit io_ring_exit_work [ 108.174205][ T14] Call trace: [ 108.175649][ T14] sanity_check_pinned_pages+0x7cc/0x7d0 (P) [ 108.178138][ T14] unpin_user_page+0x80/0x10c [ 108.180189][ T14] io_release_ubuf+0x84/0xf8 [ 108.182196][ T14] io_free_rsrc_node+0x250/0x57c [ 108.184345][ T14] io_rsrc_data_free+0x148/0x298 [ 108.186493][ T14] io_sqe_buffers_unregister+0x84/0xa0 [ 108.188991][ T14] io_ring_ctx_free+0x48/0x480 [ 108.191057][ T14] io_ring_exit_work+0x764/0x7d8 [ 108.193207][ T14] process_one_work+0x7e8/0x155c [ 108.195431][ T14] worker_thread+0x958/0xed8 [ 108.197561][ T14] kthread+0x5fc/0x75c [ 108.199362][ T14] ret_from_fork+0x10/0x20 We can pin a tail page of a folio, but then io_uring will try to unpin the head page of the folio. While it should be fine in terms of keeping the page actually alive, mm folks say it's wrong and triggers a debug warning. Use unpin_user_folio() instead of unpin_user_page*. [axboe: adapt to current tree, massage commit message]
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | linux | 6.12.37-1 | DEBIAN-CVE-2025-38256 |
| Debian:14 | linux | 6.12.37-1 | DEBIAN-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-allwinner-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-aws-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-aws-6.14 | 6.14.0-1015.15~24.04.1 | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-aws-6.2 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-aws-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-azure-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-azure-6.11 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-azure-6.14 | 6.14.0-1014.14~24.04.1 | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-azure-6.2 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-azure-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:25.10 | linux-azure-fde | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-azure-fde-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-azure-fde-6.2 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-azure-nvidia-6.14 | 6.14.0-1007.7 | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-gcp-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-gcp-6.11 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-gcp-6.14 | 6.14.0-1018.19~24.04.1 | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-gcp-6.2 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-gcp-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-hwe-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-hwe-6.11 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-hwe-6.2 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-hwe-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-intel-iot-realtime | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-lowlatency-hwe-6.11 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.2 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-lowlatency-hwe-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-nvidia-6.2 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-nvidia-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-oem-5.17 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-oem-6.0 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-oem-6.1 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-oem-6.14 | 6.14.0-1014.14 | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-oem-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-oracle-6.14 | 6.14.0-1015.15~24.04.1 | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-oracle-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-raspi-realtime | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-realtime | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-riscv | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-riscv-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:24.04:LTS | linux-riscv-6.14 | 6.14.0-34.34.1~24.04.1 | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-riscv-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-starfive-5.19 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-starfive-6.2 | no fix listed | UBUNTU-CVE-2025-38256 |
| Ubuntu:22.04:LTS | linux-starfive-6.5 | no fix listed | UBUNTU-CVE-2025-38256 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Linux | Linux | a8edbb424b1391b077407c75d8f5d2ede77aa70d – before 53fd75f25b223878b5fff14932e3a22f42b54f77a8edbb424b1391b077407c75d8f5d2ede77aa70d – before 11e7b7369e655e6131387b174218d7fa9557b3daa8edbb424b1391b077407c75d8f5d2ede77aa70d – before 5afb4bf9fc62d828647647ec31745083637132e4 |
| Linux | Linux | 6.12 |