SB20260812375 - Out-of-bounds write in Linux kernel ceph

Description

This security bulletin contains information about 1 vulnerability.

1) Out-of-bounds write (CVE-ID: CVE-2026-68159)

CWE-ID: CWE-787 - Out-of-bounds write

CVSSv4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

The vulnerability allows a remote attacker to cause a denial of service.

The vulnerability exists due to a stack out-of-bounds write in __decode_pg_temp(), __decode_pg_upmap_items(), and OSDMap handling in net/ceph/osdmap.c when processing a crafted OSDMap containing an oversized pg_temp, pg_upmap, or pg_upmap_items entry. A remote attacker can send a specially crafted OSDMap entry to cause a denial of service.

The issue is triggered when the decoded list is later copied into the fixed-size on-stack array struct ceph_osds.osds[CEPH_PG_MAX_SIZE].

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/9f00f9cf2be293efe899db67dc5272e3a9c62717
• https://git.kernel.org/stable/c/e36663145abd7024f0281dfb22fdef65f185845b