{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-39775 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-39775 is a medium-severity denial of service vulnerability in Linux kernel, published on 11 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-39775 and fix it if it is affected.\n\nWhat it is: CVE-2025-39775 is a medium-severity denial of service vulnerability in Linux kernel, published on 11 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2025-39775 in the wild and no public exploit code.\n\nAffected product: Linux kernel. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.\n2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2025-39775/ (Markdown: https://insights.sbomify.com/CVE-2025-39775/index.md)","id":"CVE-2025-39775","markdown":"https://insights.sbomify.com/CVE-2025-39775/index.md","name":"CVE-2025-39775","record":{"aliases":["BELL-CVE-2025-39775","DEBIAN-CVE-2025-39775","GHSA-mj2f-v2cm-g63m","ROOT-OS-DEBIAN-13-CVE-2025-39775","UBUNTU-CVE-2025-39775"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A local attacker can trigger a kernel warning and potential instability by using mremap on a VMA with userfaultfd, causing a denial of service.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"nvd","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm/mremap: fix WARN with uffd that has remap events disabled\n\nRegistering userfaultd on a VMA that spans at least one PMD and then\nmremap()'ing that VMA can trigger a WARN when recovering from a failed\npage table move due to a page table allocation error.\n\nThe code ends up doing the right thing (recurse, avoiding moving actual\npage tables), but triggering that WARN is unpleasant:\n\nWARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_normal_pmd mm/mremap.c:357 [inline]\nWARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_pgt_entry mm/mremap.c:595 [inline]\nWARNING: CPU: 2 PID: 6133 at mm/mremap.c:357 move_page_tables+0x3832/0x44a0 mm/mremap.c:852\nModules linked in:\nCPU: 2 UID: 0 PID: 6133 Comm: syz.0.19 Not tainted 6.17.0-rc1-syzkaller-00004-g53e760d89498 #0 PREEMPT(full)\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014\nRIP: 0010:move_normal_pmd mm/mremap.c:357 [inline]\nRIP: 0010:move_pgt_entry mm/mremap.c:595 [inline]\nRIP: 0010:move_page_tables+0x3832/0x44a0 mm/mremap.c:852\nCode: ...\nRSP: 0018:ffffc900037a76d8 EFLAGS: 00010293\nRAX: 0000000000000000 RBX: 0000000032930007 RCX: ffffffff820c6645\nRDX: ffff88802e56a440 RSI: ffffffff820c7201 RDI: 0000000000000007\nRBP: ffff888037728fc0 R08: 0000000000000007 R09: 0000000000000000\nR10: 0000000032930007 R11: 0000000000000000 R12: 0000000000000000\nR13: ffffc900037a79a8 R14: 0000000000000001 R15: dffffc0000000000\nFS:  000055556316a500(0000) GS:ffff8880d68bc000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000001b30863fff CR3: 0000000050171000 CR4: 0000000000352ef0\nCall Trace:\n \u003cTASK\u003e\n copy_vma_and_data+0x468/0x790 mm/mremap.c:1215\n move_vma+0x548/0x1780 mm/mremap.c:1282\n mremap_to+0x1b7/0x450 mm/mremap.c:1406\n do_mremap+0xfad/0x1f80 mm/mremap.c:1921\n __do_sys_mremap+0x119/0x170 mm/mremap.c:1977\n do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x77/0x7f\nRIP: 0033:0x7f00d0b8ebe9\nCode: ...\nRSP: 002b:00007ffe5ea5ee98 EFLAGS: 00000246 ORIG_RAX: 0000000000000019\nRAX: ffffffffffffffda RBX: 00007f00d0db5fa0 RCX: 00007f00d0b8ebe9\nRDX: 0000000000400000 RSI: 0000000000c00000 RDI: 0000200000000000\nRBP: 00007ffe5ea5eef0 R08: 0000200000c00000 R09: 0000000000000000\nR10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000002\nR13: 00007f00d0db5fa0 R14: 00007f00d0db5fa0 R15: 0000000000000005\n \u003c/TASK\u003e\n\nThe underlying issue is that we recurse during the original page table\nmove, but not during the recovery move.\n\nFix it by checking for both VMAs and performing the check before the\npmd_none() sanity check.\n\nAdd a new helper where we perform+document that check for the PMD and PUD\nlevel.\n\nThanks to Harry for bisecting.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"mm/mremap: fix WARN with uffd that has remap events disabled","id":"CVE-2025-39775","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2025"},"n_packages":0,"n_references":3,"next":{"headline":"mm/debug_vm_pgtable: clear page table entries at destroy_args()","id":"CVE-2025-39776"},"packages":[],"prev":{"headline":"iio: adc: rzg2l_adc: Set driver data before enabling runtime PM","id":"CVE-2025-39774"},"products":["Linux"],"published":"2025-09-11","related":[{"cvss_score":8.8,"headline":"Linux Kernel Out-of-Bounds Write","id":"CVE-2026-53266","kev_date_added":"2026-09-18","published":"2026-06-25"},{"cvss_score":8.8,"headline":"Linux Kernel Improper Input Validation","id":"CVE-2013-6282","kev_date_added":"2022-09-15","published":"2013-11-19"},{"cvss_score":8.4,"headline":"Linux Kernel Heap-Based Buffer Overflow","id":"CVE-2022-0185","kev_date_added":"2024-08-21","published":"2022-02-11"},{"cvss_score":8.4,"headline":"Linux Kernel Privilege Escalation","id":"CVE-2013-2094","kev_date_added":"2022-09-15","published":"2013-05-14"},{"cvss_score":7.8,"headline":"Linux Kernel Unspecified","id":"CVE-2026-53362","kev_date_added":"2026-08-27","published":"2026-07-04"},{"cvss_score":7.8,"headline":"Linux Kernel Missing Initialization of a Variable","id":"CVE-2026-46300","kev_date_added":"2026-10-28","published":"2026-05-23"},{"cvss_score":7.8,"headline":"Linux Kernel Race Condition","id":"CVE-2025-39964","kev_date_added":"2026-09-18","published":"2025-10-13"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-10-21","vendors":["Linux"]},"summary":"A local attacker can trigger a kernel warning and potential instability by using mremap on a VMA with userfaultfd, causing a denial of service.","url":"https://insights.sbomify.com/CVE-2025-39775/"}