{"id":"CVE-2026-80631","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: lzo: reject compressed segment that overflows the compressed input\n\nlzo_decompress_bio() validates each on-disk segment length seg_len only\nagainst the workspace…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: lzo: reject compressed segment that overflows the compressed input\n\nlzo_decompress_bio() validates each on-disk segment length seg_len only\nagainst the workspace…","severity":"high","cvss":7.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","published":"2026-08-28","updated":"2026-08-29","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80631","references":[{"url":"https://git.kernel.org/stable/c/1641d058adfbd50cf95d54581ed5d142ee82c07f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b0d27d43791b7a3057c3c4aedf9b4aa033d37c46","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00488,"epssPercentile":0.39343,"ingestedAt":"2026-08-30T03:46:30.948Z","slug":"CVE-2026-80631","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: lzo: reject compressed segment that overflows the compressed input\n\nlzo_decompress_bio() validates each on-disk segment length seg_len only\nagainst the workspace cbuf size, not against the compressed input size\n(compressed_len, the total folio bytes of the bio).  A crafted extent can\ncarry a segment whose seg_len passes the cbuf check but runs past the end\nof the bio, so copy_compressed_segment() walks off the last folio:\nget_current_folio() then returns the NULL folio from bio_next_folio(), and\nwith CONFIG_BTRFS_ASSERT disabled (default) folio_size(NULL) faults.\n\n BUG: KASAN: null-ptr-deref in lzo_decompress_bio (fs/btrfs/lzo.c:383)\n Read of size 8 at addr 0000000000000000 by task kworker/u8:1/29\n Workqueue: btrfs-endio simple_end_io_work\n  kasan_report (mm/kasan/report.c:590)\n  lzo_decompress_bio (fs/btrfs/lzo.c:383)\n  end_bbio_compressed_read (fs/btrfs/compression.c:1065)\n  btrfs_bio_end_io (fs/btrfs/bio.c:135)\n  btrfs_check_read_bio (fs/btrfs/bio.c:180 fs/btrfs/bio.c:285)\n  simple_end_io_work\n  process_one_work\n  worker_thread\n\nReject any segment whose payload would extend beyond compressed_len before\ncopying it, treating it as corruption like the other on-disk validation\nfailures in this function.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"twilight","depthScore":41,"depthScoreParts":{"impact":41.3,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}