{"id":"CVE-2026-90096","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: invalidate the correct range after O_APPEND direct write\n\nfuse_direct_write_iter() captures pos before generic_write_checks(),\nwhich moves ki_pos to EOF for O_APP…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nfuse: invalidate the correct range after O_APPEND direct write\n\nfuse_direct_write_iter() captures pos before generic_write_checks(),\nwhich moves ki_pos to EOF for O_APP…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 2b0408d0284f4ff376cf5610fa8c9905e93c2541 < 833963069adf86dcbdffd4e7d7b3171f95070b77","Linux >= 2b0408d0284f4ff376cf5610fa8c9905e93c2541 < 26d7e1f5c407b5859122b5cd47d7ebbf4b4c1cd2","Linux 7.2"],"published":"2026-09-17","updated":"2026-09-17","sourceUpdated":"2026-09-17T17:17:01.233","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90096","references":[{"url":"https://git.kernel.org/stable/c/26d7e1f5c407b5859122b5cd47d7ebbf4b4c1cd2","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/833963069adf86dcbdffd4e7d7b3171f95070b77","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"ingestedAt":"2026-09-17T16:21:47.891Z","epss":0.00189,"epssPercentile":0.08813,"slug":"CVE-2026-90096","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nfuse: invalidate the correct range after O_APPEND direct write\n\nfuse_direct_write_iter() captures pos before generic_write_checks(),\nwhich moves ki_pos to EOF for O_APPEND writes:\n\n  fuse_direct_write_iter()\n  {\n      pos = iocb->ki_pos;           /* 0 (user-supplied)       */\n      generic_write_checks();       /* ki_pos -> EOF           */\n      fuse_direct_io();             /* writes at EOF, correct  */\n      invalidate(pos, pos + res);   /* [0, res) -- wrong       */\n  }\n\nThe post-write invalidation targets a stale range instead of the\nactual written range at EOF.\n\nThis can cause data inconsistency when the file size is not\npage-aligned.  The tail page straddling EOF has a valid portion\nbefore EOF that concurrent readers can fault back in during the\nDIO write window:\n\n  Tail page (file size X not page-aligned):\n\n    page_start         X (EOF)   page_end\n    |--- valid data ----|-- stale --|\n\n  CPU0 (O_APPEND DIO writer)    CPU1 (buffered reader)\n  --------------------------    ----------------------\n  invalidate [X, X+len)\n    tail page evicted\n  FUSE_WRITE in flight ...\n                                read [page_start, X)\n                                  tail page re-faulted\n                                  [X, page_end) = stale\n  FUSE_WRITE completes\n  i_size = X + len\n  invalidate [0, len)  <- WRONG\n    tail page still cached\n                                read [X, X+len)\n                                  hits stale tail page\n                                  returns old data\n\nFix by reading pos back from iocb->ki_pos after generic_write_checks(),\nas generic_file_direct_write() does.\n\nAlso fix a typo in the comment (\"may have\" -> \"may have competed\").\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}