{"cve":"CVE-2021-47406","nvd":{"published":"2024-05-21T15:15:26.170","modified":"2026-06-17T04:17:24.020","status":"Analyzed","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 > 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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-835"],"references":["https://git.kernel.org/stable/c/1fd95c05d8f742abfe906620780aee4dbe1a2db0","https://git.kernel.org/stable/c/27e10c5d31ff1d222c7f797f1ee96d422859ba67","https://git.kernel.org/stable/c/a63474dbf692dd09b50fed592bc41f6de5f102fc","https://git.kernel.org/stable/c/1fd95c05d8f742abfe906620780aee4dbe1a2db0","https://git.kernel.org/stable/c/27e10c5d31ff1d222c7f797f1ee96d422859ba67"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47406","score":0.0025,"percentile":0.16359,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}