NULL Pointer Dereference Affecting linux-azure-6.18 package, versions <6.18.38-r0


Severity

Recommended
0.0
medium
0
10

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Threat Intelligence

EPSS
0.12% (3rd percentile)

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  • Snyk IDSNYK-CHAINGUARDLATEST-LINUXAZURE618-17940254
  • published11 Jul 2026
  • disclosed25 Jun 2026

Introduced: 25 Jun 2026

NewCVE-2026-53271  (opens in a new tab)
CWE-476  (opens in a new tab)

How to fix?

Upgrade Chainguard linux-azure-6.18 to version 6.18.38-r0 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream linux-azure-6.18 package and not the linux-azure-6.18 package as distributed by Chainguard. See How to fix? for Chainguard relevant fixed versions and status.

In the Linux kernel, the following vulnerability has been resolved:

ksmbd: fix NULL-deref of opinfo->conn in oplock/lease break notifiers

smb2_oplock_break_noti() and smb2_lease_break_noti() read opinfo->conn into a local with neither READ_ONCE() nor a NULL check. Both run from oplock_break() after opinfo_get_list() has dropped ci->m_lock, so a concurrent SMB2 LOGOFF (session_fd_check()) can set op->conn = NULL under ci->m_lock within that window. ksmbd_conn_r_count_inc(conn) then writes through NULL at offset 0xc4 -- a remotely triggerable oops.

Guard both reads the way compare_guid_key() already does: read opinfo->conn with READ_ONCE() and return early if it is NULL, before allocating the work struct so nothing leaks. A NULL conn means the client is gone and the break is moot, so return 0; oplock_break() treats that as success and runs the normal teardown.

CVSS Base Scores

version 3.1