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CVE-2026-80631— btrfs: lzo: reject compressed segment that overflows the compressed input

Quick assessment

Affected
Linux Linux
Exploitation
No confirmed in-the-wild exploitation; assess based on exposure
Recommended action
Check the vendor advisory and references for a fixed version. If immediate upgrade is impossible, restrict exposure and increase monitoring.

在 Linux 内核中，以下漏洞已得到修复： btrfs: lzo: 拒绝导致压缩输入溢出的压缩段 仅将磁盘上的每个段长度 与工作区缓冲区 的大小进行校验，而没有将其与压缩输入大小（ ，即 bio 中的总 folio 字节数）进行比较。一个精心构造的 extent 可能包含一个 虽能通过 检查，但会超出 bio 末尾的段。这导致 越过最后一个 folio：随后 会返回来自 的空 folio。当 被禁用（默认情况）时，对空指针调用 会触发内存访问违例（fault）。 BUG: KASAN 报告在 lzo_decomp

CVSS 7.5 · High EPSS 0.15% · P5

Affected Version Matrix 6

VendorProduct Version RangeStatus
Linux Linux a6e66e6f8c1b685e11b778bef614480a9c1a5278< 1641d058adfbd50cf95d54581ed5d142ee82c07f affected
a6e66e6f8c1b685e11b778bef614480a9c1a5278< b0d27d43791b7a3057c3c4aedf9b4aa033d37c46 affected
5.15 affected
< 5.15 unaffected
7.1.5≤ 7.1.* unaffected
7.2≤ * unaffected
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I. Basic Information for CVE-2026-80631

Vulnerability Information
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Vulnerability Title
btrfs: lzo: reject compressed segment that overflows the compressed input
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: btrfs: lzo: reject compressed segment that overflows the compressed input lzo_decompress_bio() validates each on-disk segment length seg_len only against the workspace cbuf size, not against the compressed input size (compressed_len, the total folio bytes of the bio). A crafted extent can carry a segment whose seg_len passes the cbuf check but runs past the end of the bio, so copy_compressed_segment() walks off the last folio: get_current_folio() then returns the NULL folio from bio_next_folio(), and with CONFIG_BTRFS_ASSERT disabled (default) folio_size(NULL) faults. BUG: KASAN: null-ptr-deref in lzo_decompress_bio (fs/btrfs/lzo.c:383) Read of size 8 at addr 0000000000000000 by task kworker/u8:1/29 Workqueue: btrfs-endio simple_end_io_work kasan_report (mm/kasan/report.c:590) lzo_decompress_bio (fs/btrfs/lzo.c:383) end_bbio_compressed_read (fs/btrfs/compression.c:1065) btrfs_bio_end_io (fs/btrfs/bio.c:135) btrfs_check_read_bio (fs/btrfs/bio.c:180 fs/btrfs/bio.c:285) simple_end_io_work process_one_work worker_thread Reject any segment whose payload would extend beyond compressed_len before copying it, treating it as corruption like the other on-disk validation failures in this function.
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux a6e66e6f8c1b685e11b778bef614480a9c1a5278 ~ 1641d058adfbd50cf95d54581ed5d142ee82c07f -
Linux Linux 5.15 -

II. Public POCs for CVE-2026-80631

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III. Intelligence Information for CVE-2026-80631

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Patches & Fixes for CVE-2026-80631 (2)

Same Patch Batch · Linux · 2026-08-28 · 135 CVEs total

CVE-2026-80634 9.8 CRITICAL netfilter: flowtable: avoid num_encaps underflow on bridge VLAN untag
CVE-2026-80694 9.8 CRITICAL net: ethernet: mtk_eth_soc: pass eth to mtk_handle_irq_rx in poll_controller
CVE-2026-80681 9.8 CRITICAL vxlan: re-fetch eth header after route_shortcircuit()
CVE-2026-80674 9.8 CRITICAL ntfs: validate resident attribute lists and harden the validator
CVE-2026-80673 9.8 CRITICAL ntfs: bound the look-ahead attribute-list entry in ntfs_external_attr_find()
CVE-2026-80668 9.8 CRITICAL netfilter: nf_conntrack_expect: use conntrack GC to reap expectations
CVE-2026-80630 9.8 CRITICAL net/sched: sch_fq_codel: Do not call qdisc_tree_reduce_backlog during peek before restorin
CVE-2026-80617 9.8 CRITICAL net: airoha: fix foe_check_time allocation size
CVE-2026-80612 9.8 CRITICAL net: lwtunnel: Drop skb metadata before LWT encapsulation
CVE-2026-80714 9.8 CRITICAL ipvs: do not propagate one-packet flag to synced conns
CVE-2026-80609 9.8 CRITICAL qede: fix out-of-bounds check for cqe->len_list[]
CVE-2026-80600 9.8 CRITICAL batman-adv: dat: acquire ARP hw source only after skb realloc
CVE-2026-80693 9.3 CRITICAL idpf: bound interrupt-vector register fill to the allocated array
CVE-2026-80684 9.3 CRITICAL KVM: s390: pci: Fix NULL dereference on AIBV allocation failure
CVE-2026-80671 9.3 CRITICAL perf sched: Fix register_pid() overflow, strcpy, and BUG_ON
CVE-2026-80603 9.1 CRITICAL netfilter: nf_conntrack_irc: fix parse_dcc() off-by-one OOB read
CVE-2026-80670 9.1 CRITICAL perf tools: Use perf_env__get_cpu_topology() in machine__resolve()
CVE-2026-80721 8.8 HIGH Bluetooth: ISO: ensure no dangling hcon references in iso_conn
CVE-2026-80722 8.8 HIGH wifi: mac80211: validate individual TWT params before driver setup
CVE-2026-80724 8.8 HIGH ptp: vmclock: prevent read-only mappings from becoming writable

Showing top 20 of 135 CVEs. View all on vendor page &rarr; →

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

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