CVE-2017-1000405
mediumpriority · track · 39EPSS 0.028 · 87 %ileexploit · PoCDEEURUUSEPSS · scored 2026-10-26
The Linux Kernel versions 2.6.38 through 4.14 have a problematic use of pmd_mkdirty() in the touch_pmd() function inside the THP implementation. touch_pmd() can be reached by get_user_pages(). In such case, the pmd will become dirty. This scenario breaks the new can_follow_write_pmd()'s logic - pmd can become dirty without going through a COW cycle. This bug is not as severe as the original "Dirty cow" because an ext4 file (or any other regular file) cannot be mapped using THP. Nevertheless, it does allow us to overwrite read-only huge pages. For example, the zero huge page and sealed shmem files can be overwritten (since their mapping can be populated using THP). Note that after the first write page-fault to the zero page, it will be replaced with a new fresh (and zeroed) thp.
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 6.6–7
weaknesses
The CWE weakness classes this flaw belongs to.
exploits (3)
Public proof-of-concept and weaponised exploit code.
affected products (24)
Products and version ranges known to be affected.
advisories (1)
Vendor and ecosystem advisories describing this.
- WID-SEC-W-2026-1693Linux Kernel: Schwachstelle ermöglicht Denial of ServiceDeutsch2017-11-29csaf · cert_bundDE
Ein lokaler Angreifer kann eine Schwachstelle im Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (20)
External citations — patches, advisories, analysis.
- http://www.securitytracker.com/id/1040020cnnvd
- https://access.redhat.com/errata/RHSA-2018:0180cnnvd
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a8f97366452ed491d13cf1e44241bc0b5740b1f0Patchcnnvd
- https://medium.com/bindecy/huge-dirty-cow-cve-2017-1000405-110eca132de0cnnvd
- https://source.android.com/security/bulletin/pixel/2018-02-01cnnvd
- https://www.auscert.org.au/bulletins/ESB-2020.4132/cnnvd
- https://www.exploit-db.com/exploits/43199/cnnvd
- https://www.securityfocus.com/bid/102032cnnvd
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