{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47274 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47274 is a high-severity memory corruption vulnerability in Linux kernel, published on 21 May 2024. 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-2021-47274 and fix it if it is affected.\n\nWhat it is: CVE-2021-47274 is a high-severity memory corruption vulnerability in Linux kernel, published on 21 May 2024. 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-2021-47274 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-2021-47274/ (Markdown: https://insights.sbomify.com/CVE-2021-47274/index.md)","id":"CVE-2021-47274","markdown":"https://insights.sbomify.com/CVE-2021-47274/index.md","name":"CVE-2021-47274","record":{"aliases":["DEBIAN-CVE-2021-47274","GHSA-px85-vjfw-cm92","UBUNTU-CVE-2021-47274"],"analysis":{"component_type":"kernel","fix_type":"patch","impacts":["denial_of_service","code_execution"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Linux kernel","requires_auth":"low_privilege","summary":"A length check error in the Linux kernel tracing subsystem allows out-of-bounds writes, leading to memory corruption and potential system crashes or code execution.","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":7.8,"severity":"high","source":"cna","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-125","name":"Out-of-bounds Read"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Correct the length check which causes memory corruption\n\nWe've suffered from severe kernel crashes due to memory corruption on\nour production environment, like,\n\nCall Trace:\n[1640542.554277] general protection fault: 0000 [#1] SMP PTI\n[1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G\n[1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190\n[1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286\n[1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX:\n0000000006e931bf\n[1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI:\nffff9a45ff004300\n[1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09:\n0000000000000000\n[1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12:\nffffffff9a20608d\n[1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15:\n696c662f65636976\n[1640542.563128] FS:  00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000)\nknlGS:0000000000000000\n[1640542.563937] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n[1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4:\n00000000003606e0\n[1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2:\n0000000000000000\n[1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7:\n0000000000000400\n[1640542.566742] Call Trace:\n[1640542.567009]  anon_vma_clone+0x5d/0x170\n[1640542.567417]  __split_vma+0x91/0x1a0\n[1640542.567777]  do_munmap+0x2c6/0x320\n[1640542.568128]  vm_munmap+0x54/0x70\n[1640542.569990]  __x64_sys_munmap+0x22/0x30\n[1640542.572005]  do_syscall_64+0x5b/0x1b0\n[1640542.573724]  entry_SYSCALL_64_after_hwframe+0x44/0xa9\n[1640542.575642] RIP: 0033:0x7f45d6e61e27\n\nJames Wang has reproduced it stably on the latest 4.19 LTS.\nAfter some debugging, we finally proved that it's due to ftrace\nbuffer out-of-bound access using a debug tool as follows:\n[   86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000\n[   86.780806]  no_context+0xdf/0x3c0\n[   86.784327]  __do_page_fault+0x252/0x470\n[   86.788367]  do_page_fault+0x32/0x140\n[   86.792145]  page_fault+0x1e/0x30\n[   86.795576]  strncpy_from_unsafe+0x66/0xb0\n[   86.799789]  fetch_memory_string+0x25/0x40\n[   86.804002]  fetch_deref_string+0x51/0x60\n[   86.808134]  kprobe_trace_func+0x32d/0x3a0\n[   86.812347]  kprobe_dispatcher+0x45/0x50\n[   86.816385]  kprobe_ftrace_handler+0x90/0xf0\n[   86.820779]  ftrace_ops_assist_func+0xa1/0x140\n[   86.825340]  0xffffffffc00750bf\n[   86.828603]  do_sys_open+0x5/0x1f0\n[   86.832124]  do_syscall_64+0x5b/0x1b0\n[   86.835900]  entry_SYSCALL_64_after_hwframe+0x44/0xa9\n\ncommit b220c049d519 (\"tracing: Check length before giving out\nthe filter buffer\") adds length check to protect trace data\noverflow introduced in 0fc1b09ff1ff, seems that this fix can't prevent\noverflow entirely, the length check should also take the sizeof\nentry-\u003earray[0] into account, since this array[0] is filled the\nlength of trace data and occupy addtional space and risk overflow.","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":"tracing: Correct the length check which causes memory corruption","id":"CVE-2021-47274","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"memory_corruption","year":"2021"},"n_packages":0,"n_references":7,"next":{"headline":"bcache: avoid oversized read request in cache missing code path","id":"CVE-2021-47275"},"packages":[],"prev":{"headline":"usb: dwc3-meson-g12a: fix usb2 PHY glue init when phy0 is disabled","id":"CVE-2021-47273"},"products":["Linux"],"published":"2024-05-21","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":"yes","exploitation":"none","technical_impact":"total"},"state":"PUBLISHED","updated":"2026-08-05","vendors":["Linux"]},"summary":"A length check error in the Linux kernel tracing subsystem allows out-of-bounds writes, leading to memory corruption and potential system crashes or code execution.","url":"https://insights.sbomify.com/CVE-2021-47274/"}