{"id":"CVE-2026-90260","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: don't clobber the extent buffer when zeroing it out\n\nOn a zoned filesystem a freed-but-still-dirty tree block is written out\nas zeros (EXTENT_BUFFER_ZONED…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: don't clobber the extent buffer when zeroing it out\n\nOn a zoned filesystem a freed-but-still-dirty tree block is written out\nas zeros (EXTENT_BUFFER_ZONED…","severity":"high","cvss":7.1,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H","vendor":"Linux","product":"Linux","affected":["Linux >= aa6313e6ff2bfbf736a2739047bba355d8241584 < 92484ad014f2e2b0e0e7bbc1610951e978cf557c","Linux >= aa6313e6ff2bfbf736a2739047bba355d8241584 < 98e3747587f9f87f010d8d7e55786216249a94af","Linux >= aa6313e6ff2bfbf736a2739047bba355d8241584 < db4b9eefc8ee0bcaeee4d5e6a7313905f6a2fe7c","Linux 6.8"],"published":"2026-09-17","updated":"2026-09-18","sourceUpdated":"2026-09-18T18:17:51.297","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-90260","references":[{"url":"https://git.kernel.org/stable/c/92484ad014f2e2b0e0e7bbc1610951e978cf557c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/98e3747587f9f87f010d8d7e55786216249a94af","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/db4b9eefc8ee0bcaeee4d5e6a7313905f6a2fe7c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00157,"epssPercentile":0.05309,"ingestedAt":"2026-09-17T16:21:47.842Z","slug":"CVE-2026-90260","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: zoned: don't clobber the extent buffer when zeroing it out\n\nOn a zoned filesystem a freed-but-still-dirty tree block is written out\nas zeros (EXTENT_BUFFER_ZONED_ZEROOUT) only to keep the zone write\npointer advancing. btree_csum_one_bio() implemented this by memzeroing\nthe extent buffer's own folios before submission.\n\nThat destroys the in-memory buffer while it may still be referenced. In\nparticular btrfs_free_tree_block() can run on it afterwards and reads\nthe header to add a delayed reference; once the header has been zeroed\nit frees bytenr 0 and corrupts the extent tree (the\nbtrfs_header_bytenr(buf) != 0 ASSERT in btrfs_free_tree_block(), or an\n\"unable to find ref\" abort). It is flaky and reproduces under fsstress,\ne.g. generic/461 and generic/013.\n\nWrite the zeros to disk from the shared zero page instead and leave the\nextent buffer content untouched, so any later reference - including the\ndelayed reference from btrfs_free_tree_block() - still sees a valid\nheader. end_bbio_meta_write() now clears writeback on the buffer's own\nfolios, as the bio no longer carries them.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":39,"depthScoreParts":{"impact":39.1,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":207221,"id":"CVE-2026-90260","ts":1789757339732,"field":"cvss","old":null,"new":"7.1"},{"seq":207220,"id":"CVE-2026-90260","ts":1789757339732,"field":"severity","old":"none","new":"high"}]}