CVE-2025-21939drm/xe/hmm: Don't dereference struct page pointers without notifier lock
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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In the Linux kernel, the following vulnerability has been resolved: drm/xe/hmm: Don't dereference struct page pointers without notifier lock The pnfs that we obtain from hmm_range_fault() point to pages that we don't have a reference on, and the guarantee that they are still in the cpu page-tables is that the notifier lock must be held and the notifier seqno is still valid. So while building the sg table and marking the pages accesses / dirty we need to hold this lock with a validated seqno. However, the lock is reclaim tainted which makes sg_alloc_table_from_pages_segment() unusable, since it internally allocates memory. Instead build the sg-table manually. For the non-iommu case this might lead to fewer coalesces, but if that's a problem it can be fixed up later in the resource cursor code. For the iommu case, the whole sg-table may still be coalesced to a single contigous device va region. This avoids marking pages that we don't own dirty and accessed, and it also avoid dereferencing struct pages that we don't own. v2: - Use assert to check whether hmm pfns are valid (Matthew Auld) - Take into account that large pages may cross range boundaries (Matthew Auld) v3: - Don't unnecessarily check for a non-freed sg-table. (Matthew Auld) - Add a missing up_read() in an error path. (Matthew Auld) (cherry picked from commit ea3e66d280ce2576664a862693d1da8fd324c317)
- CVSS
- 7.8 HIGH (v3.1, CNA)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Modified
- Record last updated
- Oct 15, 2026
- First seen by InfoSec Signals
- Oct 15, 2026
Affected products
Linux Linux linux:linux (from the name) | 81e058a3e7fd8593d076b4f26f7b8bb49f1d61e3 builds before 2a24c98f0e4cc994334598d4f3a851972064809d; from 81e058a3e7fd8593d076b4f26f7b8bb49f1d61e3 before f9326f529da7298a95643c3267f1c0fdb0db55eb; 81e058a3e7fd8593d076b4f26f7b8bb49f1d61e3 builds before 0a98219bcc961edd3388960576e4353e123b4a51 | CNA record |
linux linux_kernel linux:linux_kernel | from 6.10 before 6.12.19; from 6.13 before 6.13.7; 6.14; 6.14; 6.14; 6.14; 6.14 | NVD |
References
- https://git.kernel.org/stable/c/2a24c98f0e4cc994334598d4f3a851972064809dpatch
- https://git.kernel.org/stable/c/f9326f529da7298a95643c3267f1c0fdb0db55ebpatch
- https://git.kernel.org/stable/c/0a98219bcc961edd3388960576e4353e123b4a51patch
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.