{"id":"CVE-2026-64159","state":"PUBLISHED","title":"netfs: Fix zeropoint update where i_size > remote_i_size","description":"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 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.","publishedAt":"2026-07-19T15:40:46.400Z","updatedAt":"2026-10-21T12:43:09.056Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cce6bfa6ca0e30af9927b0074c97fe6a92f28092","status":"affected","lessThan":"f706e3889ff75877ecb3abae5ad667dbc990331e","versionType":"git"},{"version":"cce6bfa6ca0e30af9927b0074c97fe6a92f28092","status":"affected","lessThan":"5afc2d9b86bed2e4d9e1ba467790cbc793223f98","versionType":"git"},{"version":"cce6bfa6ca0e30af9927b0074c97fe6a92f28092","status":"affected","lessThan":"5cd5207de519ef0c085f4f559adf5eefcb4c5202","versionType":"git"},{"version":"cce6bfa6ca0e30af9927b0074c97fe6a92f28092","status":"affected","lessThan":"4543a4d737944134a1394afe797622546fbcc98a","versionType":"git"},{"version":"e2814004138a541110d4b2dc254a8f619c2c4ce0","status":"affected","versionType":"git"},{"version":"6.10.8","status":"affected","lessThan":"6.11","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/netfs/misc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.11","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/netfs/misc.c"]}],"references":["https://git.kernel.org/stable/c/f706e3889ff75877ecb3abae5ad667dbc990331e","https://git.kernel.org/stable/c/5afc2d9b86bed2e4d9e1ba467790cbc793223f98","https://git.kernel.org/stable/c/5cd5207de519ef0c085f4f559adf5eefcb4c5202","https://git.kernel.org/stable/c/4543a4d737944134a1394afe797622546fbcc98a"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:41.951Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/64xxx/CVE-2026-64159.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-64159","state":"PUBLISHED","datePublished":"2026-07-19T15:40:46.400Z","dateUpdated":"2026-10-21T12:43:09.056Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-19T07:54:57.038Z"},"containers":{"cna":{"title":"netfs: Fix zeropoint update where i_size > remote_i_size","descriptions":[{"lang":"en","value":"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 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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"cce6bfa6ca0e30af9927b0074c97fe6a92f28092","status":"affected","lessThan":"f706e3889ff75877ecb3abae5ad667dbc990331e","versionType":"git"},{"version":"cce6bfa6ca0e30af9927b0074c97fe6a92f28092","status":"affected","lessThan":"5afc2d9b86bed2e4d9e1ba467790cbc793223f98","versionType":"git"},{"version":"cce6bfa6ca0e30af9927b0074c97fe6a92f28092","status":"affected","lessThan":"5cd5207de519ef0c085f4f559adf5eefcb4c5202","versionType":"git"},{"version":"cce6bfa6ca0e30af9927b0074c97fe6a92f28092","status":"affected","lessThan":"4543a4d737944134a1394afe797622546fbcc98a","versionType":"git"},{"version":"e2814004138a541110d4b2dc254a8f619c2c4ce0","status":"affected","versionType":"git"},{"version":"6.10.8","status":"affected","lessThan":"6.11","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/netfs/misc.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.11","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.11","versionType":"semver"},{"version":"6.12.114","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.57","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.11","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/netfs/misc.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/f706e3889ff75877ecb3abae5ad667dbc990331e"},{"url":"https://git.kernel.org/stable/c/5afc2d9b86bed2e4d9e1ba467790cbc793223f98"},{"url":"https://git.kernel.org/stable/c/5cd5207de519ef0c085f4f559adf5eefcb4c5202"},{"url":"https://git.kernel.org/stable/c/4543a4d737944134a1394afe797622546fbcc98a"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:43:09.056Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.12.114"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"6.18.57"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"7.0.11"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.11","versionEndExcluding":"7.1"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10.8"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}