{"answers":{"affected":"","exploited":"There is no known exploitation of CVE-2025-40009 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-40009 is a vulnerability in Linux, published on 20 Oct 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-2025-40009 and fix it if it is affected.\n\nWhat it is: CVE-2025-40009 is a vulnerability in Linux, published on 20 Oct 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-2025-40009 in the wild and no public exploit code.\n\nAffected product: Linux. 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-2025-40009/ (Markdown: https://insights.sbomify.com/CVE-2025-40009/index.md)","id":"CVE-2025-40009","markdown":"https://insights.sbomify.com/CVE-2025-40009/index.md","name":"CVE-2025-40009","record":{"aliases":["BELL-CVE-2025-40009","DEBIAN-CVE-2025-40009","GHSA-cmvf-g3gj-cgc9","ROOT-OS-DEBIAN-13-CVE-2025-40009","ROOT-OS-UBUNTU-2404-CVE-2025-40009","UBUNTU-CVE-2025-40009"],"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 panic via a specific ioctl call, causing a denial of service.","user_interaction":"not_required","vuln_class":"null_dereference"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\nfs/proc/task_mmu: check p-\u003evec_buf for NULL\n\nWhen the PAGEMAP_SCAN ioctl is invoked with vec_len = 0 reaches\npagemap_scan_backout_range(), kernel panics with null-ptr-deref:\n\n[   44.936808] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI\n[   44.937797] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n[   44.938391] CPU: 1 UID: 0 PID: 2480 Comm: reproducer Not tainted 6.17.0-rc6 #22 PREEMPT(none)\n[   44.939062] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014\n[   44.939935] RIP: 0010:pagemap_scan_thp_entry.isra.0+0x741/0xa80\n\n\u003csnip registers, unreliable trace\u003e\n\n[   44.946828] Call Trace:\n[   44.947030]  \u003cTASK\u003e\n[   44.949219]  pagemap_scan_pmd_entry+0xec/0xfa0\n[   44.952593]  walk_pmd_range.isra.0+0x302/0x910\n[   44.954069]  walk_pud_range.isra.0+0x419/0x790\n[   44.954427]  walk_p4d_range+0x41e/0x620\n[   44.954743]  walk_pgd_range+0x31e/0x630\n[   44.955057]  __walk_page_range+0x160/0x670\n[   44.956883]  walk_page_range_mm+0x408/0x980\n[   44.958677]  walk_page_range+0x66/0x90\n[   44.958984]  do_pagemap_scan+0x28d/0x9c0\n[   44.961833]  do_pagemap_cmd+0x59/0x80\n[   44.962484]  __x64_sys_ioctl+0x18d/0x210\n[   44.962804]  do_syscall_64+0x5b/0x290\n[   44.963111]  entry_SYSCALL_64_after_hwframe+0x76/0x7e\n\nvec_len = 0 in pagemap_scan_init_bounce_buffer() means no buffers are\nallocated and p-\u003evec_buf remains set to NULL.\n\nThis breaks an assumption made later in pagemap_scan_backout_range(), that\npage_region is always allocated for p-\u003evec_buf_index.\n\nFix it by explicitly checking p-\u003evec_buf for NULL before dereferencing.\n\nOther sites that might run into same deref-issue are already (directly or\ntransitively) protected by checking p-\u003evec_buf.\n\nNote:\nFrom PAGEMAP_SCAN man page, it seems vec_len = 0 is valid when no output\nis requested and it's only the side effects caller is interested in,\nhence it passes check in pagemap_scan_get_args().\n\nThis issue was found by syzkaller.","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":"fs/proc/task_mmu: check p-\u003evec_buf for NULL","id":"CVE-2025-40009","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"null_dereference","year":"2025"},"n_packages":0,"n_references":3,"next":{"headline":"afs: Fix potential null pointer dereference in afs_put_server","id":"CVE-2025-40010"},"packages":[],"prev":{"headline":"kmsan: fix out-of-bounds access to shadow memory","id":"CVE-2025-40008"},"products":["Linux"],"published":"2025-10-20","related":[],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A local attacker can trigger a kernel panic via a specific ioctl call, causing a denial of service.","url":"https://insights.sbomify.com/CVE-2025-40009/"}