{"cve":"CVE-2026-53165","nvd":{"published":"2026-06-25T09:16:33.893","modified":"2026-07-07T18:14:02.510","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\niomap: avoid potential null folio->mapping deref during error reporting\n\nWhen a buffered read fails, iomap_finish_folio_read() reports the error\nwith fserror_report_io(folio->mapping->host, ...). This is called after\nifs->read_bytes_pending has been decremented by the bytes attempted to\nbe read.\n\nFor a folio split across multiple read completions, the folio is only\nguaranteed to stay locked while read_bytes_pending > 0. Once\niomap_finish_folio_read() decrements read_bytes_pending, another\nin-flight read can complete and end the read on the folio, which unlocks\nit. This allows truncate logic to run and detach the folio (set\nfolio->mapping to NULL). The error reporting path then can dereference a\nNULL folio->mapping. As reported by Sam Sun, this is the race that can\noccur:\n\nCPU0: failed completion      CPU1: final completion     CPU2: truncate\n-----------------------      ----------------------     --------------\nread_bytes_pending -= len\nfinished = false\n/* preempted before\n   fserror_report_io() */\n\t\t\t     read_bytes_pending -= len\n\t\t\t     finished = true\n\t\t\t     folio_end_read()\n\t\t\t\t\t\t\ttruncate clears\n\t\t\t\t\t\t\tfolio->mapping\nfserror_report_io(\n  folio->mapping->host, ...)\n\t      ^ NULL deref\n\nFix this by reporting the error first before decrementing\nifs->read_bytes_pending.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/1ad453817a4077230d1ba88eb0868f05f824449a","https://git.kernel.org/stable/c/2eea7f44b9c8b42fd7d3a1a87c06a7cd1b99c327"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:41:17.107060303+00:00"},"epss":{"cve":"CVE-2026-53165","score":0.00488,"percentile":0.42018,"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."]}