Goal Reached Thanks to every supporter — we hit 100%!

Goal: 1000 CNY · Raised: 1359 CNY

100%
Buy Us a Coffee

CVE-2026-68082— libceph: fix two unsafe bare decodes in decode_lockers()

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.

Linux kernel是美国Linux基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于libceph的decode_lockers函数中存在两个不安全的解码操作，缺少边界检查，可能导致恶意或受损的OSD触发越界读取，造成信息泄露。

CVSS 9.8 · Critical EPSS 0.40% · P33

Affected Version Matrix 18

VendorProduct Version RangeStatus
Linux Linux d4ed4a530562881cc5225050e42d96034f405aae< c8ade01170a27d8ede0d761c255268af81e417f8 affected
d4ed4a530562881cc5225050e42d96034f405aae< 001835c599899ef1bd3506a815110a6374451554 affected
d4ed4a530562881cc5225050e42d96034f405aae< 7c422364acd93d7da1dfc27d6b54635a269653a1 affected
d4ed4a530562881cc5225050e42d96034f405aae< 02430f6f729b297e803d0605871f0a670b4eafd6 affected
d4ed4a530562881cc5225050e42d96034f405aae< 57ba829804fe6d34bbac3b826c4b15c1caa54862 affected
d4ed4a530562881cc5225050e42d96034f405aae< 89df5d71f83f8e2781286798fd8ae5e42cf5f1a7 affected
d4ed4a530562881cc5225050e42d96034f405aae< a54be593d0b749161b08a1e56189b2cb9114267a affected
d4ed4a530562881cc5225050e42d96034f405aae< a109a556115271ca7896dcda7b4b7e45e156c227 affected
… +10 more rows
Get alerts for future matching vulnerabilities Log in to subscribe

I. Basic Information for CVE-2026-68082

Vulnerability Information
Have questions about the vulnerability? See if Shenlong's analysis helps!
View Shenlong Deep Dive ↗

Although we use advanced large model technology, its output may still contain inaccurate or outdated information.Shenlong tries to ensure data accuracy, but please verify and judge based on the actual situation.

Vulnerability Title
libceph: fix two unsafe bare decodes in decode_lockers()
Source: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: libceph: fix two unsafe bare decodes in decode_lockers() decode_lockers() in cls_lock_client.c contains two bare decode operations that allow a malicious or compromised OSD to trigger slab-out-of-bounds reads: 1. ceph_decode_32(p) at the num_lockers field has no preceding bounds check. ceph_start_decoding() accepts struct_len=0 as valid -- the internal ceph_decode_need(p, end, 0, bad) always passes -- so when an OSD sends struct_len=0, ceph_start_decoding() returns success with p == end. The immediately following bare ceph_decode_32(p) then reads 4 bytes past the validated buffer boundary. The garbage value is passed directly to kzalloc_objs() as the locker count. The sibling function decode_watchers() in osd_client.c already uses ceph_decode_32_safe() after its own ceph_start_decoding() call. decode_lockers() was the only site using the bare variant. 2. ceph_decode_8(p) after the decode_locker() loop has no preceding bounds check. If an OSD crafts num_lockers such that the loop advances p exactly to end, the subsequent bare ceph_decode_8(p) reads one byte past the validated buffer boundary. The result is passed directly into *type, which is used as a lock type discriminator by callers, giving an OSD-controlled one-byte OOB read with direct influence over the lock type field. Fix both by replacing bare operations with their safe variants: ceph_decode_32(p) -> ceph_decode_32_safe(p, end, *num_lockers, err_inval) ceph_decode_8(p) -> ceph_decode_8_safe(p, end, *type, err_free_lockers) The goto targets differ intentionally: err_inval: is a new label returning -EINVAL directly. It is used for the pre-allocation failure path where *lockers is not yet allocated and must not be passed to ceph_free_lockers(). err_free_lockers: is the existing label. It is used for the post-allocation failure path where *lockers is allocated and must be freed. ret is set to -EINVAL before ceph_decode_8_safe() so that err_free_lockers returns the correct error code on bounds violation. Without this, err_free_lockers would return a stale ret value (0 from the successful decode_locker() loop), silently swallowing the error. -EINVAL is correct for both failure paths. The data received from the OSD is structurally malformed. -ENOMEM would misrepresent the failure class to callers and to stable@ backporters triaging error paths. Attacker model: a malicious or compromised OSD in a multi-tenant Ceph deployment can trigger this against any kernel client that issues the lock.get_info class method (e.g. during RBD exclusive lock acquisition). [ idryomov: trim changelog, formatting ]
Source: CVE Program / CVE List V5
CVSS Information
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source: CVE Program / CVE List V5
Vulnerability Type
N/A
Source: CVE Program / CVE List V5
Vulnerability Title
Linux kernel 安全漏洞
Source: CNNVD (China National Vulnerability Database)
Vulnerability Description
Linux kernel是美国Linux基金会开源的一款操作系统内核。 Linux kernel存在安全漏洞，该漏洞源于libceph的decode_lockers函数中存在两个不安全的解码操作，缺少边界检查，可能导致恶意或受损的OSD触发越界读取，造成信息泄露。
Source: CNNVD (China National Vulnerability Database)
CVSS Information
N/A
Source: CNNVD (China National Vulnerability Database)
Vulnerability Type
N/A
Source: CNNVD (China National Vulnerability Database)

Affected Products

Vendor Product Affected Versions CPE Subscribe
Linux Linux d4ed4a530562881cc5225050e42d96034f405aae ~ c8ade01170a27d8ede0d761c255268af81e417f8 -
Linux Linux 4.9 -

II. Public POCs for CVE-2026-68082

# POC Description Source Link Shenlong Link
AI-Generated POC Premium

No public POC found.

Login to generate AI POC

III. Intelligence Information for CVE-2026-68082

请登录查看更多情报信息。

Patches & Fixes for CVE-2026-68082 (7)

IV. Related Vulnerabilities

Same product: Linux
Same vendor: Linux

V. Comments for CVE-2026-68082

No comments yet

Leave a comment