{"id":"CVE-2026-64159","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix zeropoint update where i_size > remote_i_size\n\nFix the update of the zero point[*] by netfs_release_folio() when there is\nuncommitted data in the pagecache b…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix zeropoint update where i_size > remote_i_size\n\nFix the update of the zero point[*] by netfs_release_folio() when there is\nuncommitted data in the pagecache b…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 6.10.8, < 6.11","linux_kernel >= 6.11.1, < 7.0.11","linux_kernel = 6.11","linux_kernel = 7.1"],"patched":["linux_kernel 7.0.11"],"published":"2026-07-19","updated":"2026-10-15","sourceUpdated":"2026-10-15T11:17:39.663","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64159","references":[{"url":"https://git.kernel.org/stable/c/4543a4d737944134a1394afe797622546fbcc98a","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5afc2d9b86bed2e4d9e1ba467790cbc793223f98","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5cd5207de519ef0c085f4f559adf5eefcb4c5202","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00143,"epssPercentile":0.03221,"ingestedAt":"2026-10-15T11:00:41.693Z","slug":"CVE-2026-64159","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetfs: Fix zeropoint update where i_size > remote_i_size\n\nFix the update of the zero point[*] by netfs_release_folio() when there is\nuncommitted data in the pagecache beyond the folio being released but the\non-server EOF is in this folio (ie. i_size > remote_i_size).  The update\nneeds to limit zero_point to remote_i_size, not i_size as i_size is a local\nphenomenon reflecting updates made locally to the pagecache, not stuff\nwritten to the server.  remote_i_size tracks the server's i_size.\n\n[*] The zero point is the file position from which we can assume that the\n    server will just return zeros, so we can avoid generating reads.\n\nNote that netfs_invalidate_folio() probably doesn't need fixing as\nzero_point should be updated by setattr after truncation or fallocate.\n\nFound with:\n\n    fsx -q -N 1000000 -p 10000 -o 128000 -l 600000 \\\n        /xfstest.test/junk --replay-ops=junk.fsxops\n\nusing the following as junk.fsxops:\n\n    truncate 0x0 0x1bbae 0x82864\n    write 0x3ef2e 0xf9c8 0x1bbae\n    write 0x67e05 0xcb5a 0x4e8f6\n    mapread 0x57781 0x85b6 0x7495f\n    copy_range 0x5d3d 0x10329 0x54fac 0x7495f\n    write 0x64710 0x1c2b 0x7495f\n    mapread 0x64000 0x1000 0x7495f\n\non cifs with the default cache option.\n\nIt shows read-gaps on folio 0x64 failing with a short read (ie. it hits\nEOF) if the FMODE_READ check is commented out in netfs_perform_write():\n\n                if (//(file->f_mode & FMODE_READ) ||\n                    netfs_is_cache_enabled(ctx)) {\n\nand no fscache.  This was initially found with the generic/522 xfstest.\n\n## Affected\n\n- `linux_kernel >= 6.10.8, < 6.11`\n- `linux_kernel >= 6.11.1, < 7.0.11`\n- `linux_kernel = 6.11`\n- `linux_kernel = 7.1`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.0.11`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":222326,"id":"CVE-2026-64159","ts":1792065883378,"field":"cvss","old":null,"new":"5.5"},{"seq":222325,"id":"CVE-2026-64159","ts":1792065883378,"field":"severity","old":"none","new":"medium"}]}