{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-21866 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2025-21866 is a medium-severity memory corruption vulnerability in Linux kernel, published on 12 Mar 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-2025-21866 and fix it if it is affected.\n\nWhat it is: CVE-2025-21866 is a medium-severity memory corruption vulnerability in Linux kernel, published on 12 Mar 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-2025-21866 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-2025-21866/ (Markdown: https://insights.sbomify.com/CVE-2025-21866/index.md)","id":"CVE-2025-21866","markdown":"https://insights.sbomify.com/CVE-2025-21866/index.md","name":"CVE-2025-21866","record":{"aliases":["BELL-CVE-2025-21866","DEBIAN-CVE-2025-21866","GHSA-p4mq-5hwr-hc6r","ROOT-OS-DEBIAN-11-CVE-2025-21866","ROOT-OS-UBUNTU-2404-CVE-2025-21866","UBUNTU-CVE-2025-21866"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":true,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A KASAN vmalloc-out-of-bounds write in the PowerPC code patching area can cause a kernel crash during BPF JIT compilation.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"Linux","cpe":[{"product":"linux_kernel","vendor":"linux"}],"cvss":{"score":5.5,"severity":"medium","source":"cisa-adp","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC\n\nErhard reported the following KASAN hit while booting his PowerMac G4\nwith a KASAN-enabled kernel 6.13-rc6:\n\n  BUG: KASAN: vmalloc-out-of-bounds in copy_to_kernel_nofault+0xd8/0x1c8\n  Write of size 8 at addr f1000000 by task chronyd/1293\n\n  CPU: 0 UID: 123 PID: 1293 Comm: chronyd Tainted: G        W          6.13.0-rc6-PMacG4 #2\n  Tainted: [W]=WARN\n  Hardware name: PowerMac3,6 7455 0x80010303 PowerMac\n  Call Trace:\n  [c2437590] [c1631a84] dump_stack_lvl+0x70/0x8c (unreliable)\n  [c24375b0] [c0504998] print_report+0xdc/0x504\n  [c2437610] [c050475c] kasan_report+0xf8/0x108\n  [c2437690] [c0505a3c] kasan_check_range+0x24/0x18c\n  [c24376a0] [c03fb5e4] copy_to_kernel_nofault+0xd8/0x1c8\n  [c24376c0] [c004c014] patch_instructions+0x15c/0x16c\n  [c2437710] [c00731a8] bpf_arch_text_copy+0x60/0x7c\n  [c2437730] [c0281168] bpf_jit_binary_pack_finalize+0x50/0xac\n  [c2437750] [c0073cf4] bpf_int_jit_compile+0xb30/0xdec\n  [c2437880] [c0280394] bpf_prog_select_runtime+0x15c/0x478\n  [c24378d0] [c1263428] bpf_prepare_filter+0xbf8/0xc14\n  [c2437990] [c12677ec] bpf_prog_create_from_user+0x258/0x2b4\n  [c24379d0] [c027111c] do_seccomp+0x3dc/0x1890\n  [c2437ac0] [c001d8e0] system_call_exception+0x2dc/0x420\n  [c2437f30] [c00281ac] ret_from_syscall+0x0/0x2c\n  --- interrupt: c00 at 0x5a1274\n  NIP:  005a1274 LR: 006a3b3c CTR: 005296c8\n  REGS: c2437f40 TRAP: 0c00   Tainted: G        W           (6.13.0-rc6-PMacG4)\n  MSR:  0200f932 \u003cVEC,EE,PR,FP,ME,IR,DR,RI\u003e  CR: 24004422  XER: 00000000\n\n  GPR00: 00000166 af8f3fa0 a7ee3540 00000001 00000000 013b6500 005a5858 0200f932\n  GPR08: 00000000 00001fe9 013d5fc8 005296c8 2822244c 00b2fcd8 00000000 af8f4b57\n  GPR16: 00000000 00000001 00000000 00000000 00000000 00000001 00000000 00000002\n  GPR24: 00afdbb0 00000000 00000000 00000000 006e0004 013ce060 006e7c1c 00000001\n  NIP [005a1274] 0x5a1274\n  LR [006a3b3c] 0x6a3b3c\n  --- interrupt: c00\n\n  The buggy address belongs to the virtual mapping at\n   [f1000000, f1002000) created by:\n   text_area_cpu_up+0x20/0x190\n\n  The buggy address belongs to the physical page:\n  page: refcount:1 mapcount:0 mapping:00000000 index:0x0 pfn:0x76e30\n  flags: 0x80000000(zone=2)\n  raw: 80000000 00000000 00000122 00000000 00000000 00000000 ffffffff 00000001\n  raw: 00000000\n  page dumped because: kasan: bad access detected\n\n  Memory state around the buggy address:\n   f0ffff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n   f0ffff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00\n  \u003ef1000000: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n             ^\n   f1000080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n   f1000100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8\n  ==================================================================\n\nf8 corresponds to KASAN_VMALLOC_INVALID which means the area is not\ninitialised hence not supposed to be used yet.\n\nPowerpc text patching infrastructure allocates a virtual memory area\nusing get_vm_area() and flags it as VM_ALLOC. But that flag is meant\nto be used for vmalloc() and vmalloc() allocated memory is not\nsupposed to be used before a call to __vmalloc_node_range() which is\nnever called for that area.\n\nThat went undetected until commit e4137f08816b (\"mm, kasan, kmsan:\ninstrument copy_from/to_kernel_nofault\")\n\nThe area allocated by text_area_cpu_up() is not vmalloc memory, it is\nmapped directly on demand when needed by map_kernel_page(). There is\nno VM flag corresponding to such usage, so just pass no flag. That way\nthe area will be unpoisonned and usable immediately.","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":"powerpc/code-patching: Fix KASAN hit by not flagging text patching area as VM_ALLOC","id":"CVE-2025-21866","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"memory_corruption","year":"2025"},"n_packages":0,"n_references":8,"next":{"headline":"bpf, test_run: Fix use-after-free issue in eth_skb_pkt_type()","id":"CVE-2025-21867"},"packages":[],"prev":{"headline":"gtp: Suppress list corruption splat in gtp_net_exit_batch_rtnl().","id":"CVE-2025-21865"},"products":["Linux"],"published":"2025-03-12","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":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A KASAN vmalloc-out-of-bounds write in the PowerPC code patching area can cause a kernel crash during BPF JIT compilation.","url":"https://insights.sbomify.com/CVE-2025-21866/"}