{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-47406 in the wild and no public exploit code.","fix":"Apply the vendor's patch.","what":"CVE-2021-47406 is a medium-severity denial of service 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-2021-47406 and fix it if it is affected.\n\nWhat it is: CVE-2021-47406 is a medium-severity denial of service 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-2021-47406 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-2021-47406/ (Markdown: https://insights.sbomify.com/CVE-2021-47406/index.md)","id":"CVE-2021-47406","markdown":"https://insights.sbomify.com/CVE-2021-47406/index.md","name":"CVE-2021-47406","record":{"aliases":["DEBIAN-CVE-2021-47406","GHSA-95jj-pjw6-q9fr","UBUNTU-CVE-2021-47406"],"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 corrupted filesystem can cause an infinite loop in the Linux kernel ext4 fast commit replay, leading to a system hang.","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":"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-835","name":"Loop with Unreachable Exit Condition"}],"description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: add error checking to ext4_ext_replay_set_iblocks()\n\nIf the call to ext4_map_blocks() fails due to an corrupted file\nsystem, ext4_ext_replay_set_iblocks() can get stuck in an infinite\nloop.  This could be reproduced by running generic/526 with a file\nsystem that has inline_data and fast_commit enabled.  The system will\nrepeatedly log to the console:\n\nEXT4-fs warning (device dm-3): ext4_block_to_path:105: block 1074800922 \u003e max in inode 131076\n\nand the stack that it gets stuck in is:\n\n   ext4_block_to_path+0xe3/0x130\n   ext4_ind_map_blocks+0x93/0x690\n   ext4_map_blocks+0x100/0x660\n   skip_hole+0x47/0x70\n   ext4_ext_replay_set_iblocks+0x223/0x440\n   ext4_fc_replay_inode+0x29e/0x3b0\n   ext4_fc_replay+0x278/0x550\n   do_one_pass+0x646/0xc10\n   jbd2_journal_recover+0x14a/0x270\n   jbd2_journal_load+0xc4/0x150\n   ext4_load_journal+0x1f3/0x490\n   ext4_fill_super+0x22d4/0x2c00\n\nWith this patch, generic/526 still fails, but system is no longer\nlocking up in a tight loop.  It's likely the root casue is that\nfast_commit replay is corrupting file systems with inline_data, and we\nprobably need to add better error handling in the fast commit replay\ncode path beyond what is done here, which essentially just breaks the\ninfinite loop without reporting the to the higher levels of the code.","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":"ext4: add error checking to ext4_ext_replay_set_iblocks()","id":"CVE-2021-47406","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"linux:linux_kernel","products":["linux:linux_kernel"],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"KVM: x86: Handle SRCU initialization failure during page track init","id":"CVE-2021-47407"},"packages":[],"prev":{"headline":"HID: usbhid: free raw_report buffers in usbhid_stop","id":"CVE-2021-47405"},"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":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-05-11","vendors":["Linux"]},"summary":"A corrupted filesystem can cause an infinite loop in the Linux kernel ext4 fast commit replay, leading to a system hang.","url":"https://insights.sbomify.com/CVE-2021-47406/"}