rootpwn

high · CVSS v3 7.8

CVE-2026-93110

A high‑severity flaw in the Linux kernel’s RDMA core module allows a use‑after‑free condition when a module is unloaded while RCU callbacks

Overview

A high‑severity flaw in the Linux kernel’s RDMA core module allows a use‑after‑free condition when a module is unloaded while RCU callbacks are still queued. The bug can cause kernel crashes or, in the worst case, arbitrary code execution if an attacker can trigger the callback after the module is gone.

Description

In the Linux kernel, the following vulnerability has been resolved: RDMA/core: Wait for RCU callbacks before unloading ib_core put_gid_ndev() is queued with call_rcu() and implemented in ib_core. Stopping the workqueues does not drain callbacks already queued, so RCU could invoke it after the module code has been unloaded. synchronize_rcu() does not wait for callbacks. Wait for them after all producers have stopped.

Impact

The vulnerability can lead to a kernel panic or denial of service, and if an attacker can control the queued callback, it may allow arbitrary code execution with kernel privileges. It primarily affects confidentiality, integrity, and availability of the host system.

Remediation

['Apply the latest kernel update that includes the RCU callback fix for ib_core.', 'If immediate patching is not possible, disable RDMA support (`modprobe -r rdma_cm` or blacklist the RDMA modules) to prevent the callback from being queued.', 'Ensure that any custom kernel modules that interact with RDMA are updated or removed until the patch is applied.', 'Verify that `synchronize_rcu()` is used correctly in any custom code that may unload modules while RCU callbacks are pending.', 'Monitor system logs for RCU or kernel panic messages and apply the fix as soon as possible.']

Risk context

High severity (CVSS 7.8). No EPSS data available, but the flaw can cause a kernel crash or privilege escalation if an attacker can trigger the RCU callback after module unload. Prompt patching is recommended to avoid potential downtime or compromise.

Affected products

  • Linux kernel
  • Red Hat Enterprise Linux
  • Ubuntu
  • CentOS
  • Debian
  • Fedora
  • SUSE Linux Enterprise Server
  • Oracle Linux

Scores

Severity
high
CVSS v2
3.6
CVSS v3
7.8
CVSS v4
—
EPSS
—

Linux kernel RCU RDMA module-unload use-after-free high-severity

← All CVEs

Related CVEs

high

CVE-2026-93203

A race condition in the batman-adv kernel module can corrupt the CRC used to validate claim frames, leading to incorrect routing information in mesh networks. The flaw may cause routing tables to become inconsistent, potentially disrupting network connectivity.

View analysis

high

CVE-2026-93111

In the Linux kernel, the following vulnerability has been resolved: bpf: Mark tracing_multi trampolines as ftrace managed Since tracing_multi link does not set ftrace_managed, it would fail to release the tracing_multi link when attaching tracing_multi link and then attaching fentry link. [ 3.714215] WARNING: kernel/bpf/trampoline.c:1727 at bpf_trampoline_multi_detach+0x20b/0x240, CPU#1: test_progs/97 ... [ 3.733170] bpf_tracing_multi_link_release+0x14/0x30 [ 3.733890] bpf_link_free+0x58/0x130 [ 3.734414] bpf_link_release+0x23/0x30 Fix it by setting 'ftrace_managed = true' in register_fentry_multi().

View analysis

high

CVE-2026-93117

A use‑after‑free flaw in the Linux kernel’s USB subsystem could be triggered when a USB device probe runs concurrently with the removal of a dynamic ID. The issue allows an attacker to potentially cause a crash or gain elevated privileges by manipulating USB devices during the probe phase.

View analysis

high

CVE-2026-93120

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: configfs: fix out-of-bounds read of qw_sign os_desc_qw_sign_show() passes OS_STRING_QW_SIGN_LEN as the input length to utf16s_to_utf8s(), but that argument counts UTF-16 code units while OS_STRING_QW_SIGN_LEN (14) is the byte size of qw_sign[]. The array holds only OS_STRING_QW_SIGN_LEN / 2 (7) code units, so the conversion reads up to 7 units (14 bytes) past the end of qw_sign[] into the following members of struct gadget_info when the stored signature fills the array without a NUL terminator, exposing those bytes through the configfs attribute. The store path halves the count for its input bound but passes the full byte count as the utf8s_to_utf16s() output limit; use the destination code-unit count in both directions.

View analysis