UBUNTU-CVE-2025-38256
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]
02 / AFFECTED SOFTWARE
Affected packages
11 explicit affected versions
50 explicit affected versions
6 explicit affected versions
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35 explicit affected versions
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12 explicit affected versions
7 explicit affected versions
7 explicit affected versions
12 explicit affected versions
14 explicit affected versions
10 explicit affected versions
1 explicit affected versions
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12 explicit affected versions
12 explicit affected versions
9 explicit affected versions
10 explicit affected versions
37 explicit affected versions
13 explicit affected versions
2 explicit affected versions
10 explicit affected versions
7 explicit affected versions
26 explicit affected versions
13 explicit affected versions
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13 explicit affected versions
8 explicit affected versions
33 explicit affected versions
23 explicit affected versions
10 explicit affected versions
11 explicit affected versions
12 explicit affected versions
7 explicit affected versions
12 explicit affected versions
3 explicit affected versions
10 explicit affected versions
26 explicit affected versions
7 explicit affected versions
13 explicit affected versions
16 explicit affected versions
3 explicit affected versions
7 explicit affected versions
51 explicit affected versions
12 explicit affected versions
27 explicit affected versions
8 explicit affected versions
5 explicit affected versions
8 explicit affected versions
10 explicit affected versions
7 explicit affected versions
13 explicit affected versions
13 explicit affected versions
7 explicit affected versions
10 explicit affected versions
12 explicit affected versions
5 explicit affected versions
44 explicit affected versions
16 explicit affected versions
3 explicit affected versions
13 explicit affected versions
26 explicit affected versions
45 explicit affected versions
37 explicit affected versions
14 explicit affected versions
38 explicit affected versions
9 explicit affected versions
11 explicit affected versions
7 explicit affected versions
4 explicit affected versions
1 explicit affected versions
13 explicit affected versions
43 explicit affected versions
10 explicit affected versions
8 explicit affected versions
14 explicit affected versions
4 explicit affected versions
78 explicit affected versions
11 explicit affected versions
1 explicit affected versions
03 / CONNECTIONS
Connected vulnerabilities
04 / EVIDENCE
Source records
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]
05 / REFERENCES
Further evidence
- https://git.kernel.org/linus/5afb4bf9fc62d828647647ec31745083637132e4
- https://git.kernel.org/stable/c/11e7b7369e655e6131387b174218d7fa9557b3da
- https://git.kernel.org/stable/c/53fd75f25b223878b5fff14932e3a22f42b54f77
- https://git.kernel.org/stable/c/5afb4bf9fc62d828647647ec31745083637132e4
- https://ubuntu.com/security/CVE-2025-38256
- https://ubuntu.com/security/notices/USN-7833-1
- https://ubuntu.com/security/notices/USN-7833-2
- https://ubuntu.com/security/notices/USN-7833-3
- https://ubuntu.com/security/notices/USN-7833-4
- https://ubuntu.com/security/notices/USN-7834-1
- https://ubuntu.com/security/notices/USN-7856-1
- https://www.cve.org/CVERecord?id=CVE-2025-38256