CVE-2021-47459 Affecting kernel-devel package, versions <0:5.14.0-427.28.1.el9_4


Severity

Recommended
medium

Based on AlmaLinux security rating.

Threat Intelligence

EPSS
0.05% (18th percentile)

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  • Snyk IDSNYK-ALMALINUX9-KERNELDEVEL-8325861
  • published4 Nov 2024
  • disclosed31 Jul 2024

Introduced: 31 Jul 2024

CVE-2021-47459  (opens in a new tab)

How to fix?

Upgrade AlmaLinux:9 kernel-devel to version 0:5.14.0-427.28.1.el9_4 or higher.
This issue was patched in ALSA-2024:4928.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-devel package and not the kernel-devel package as distributed by AlmaLinux. See How to fix? for AlmaLinux:9 relevant fixed versions and status.

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

can: j1939: j1939_netdev_start(): fix UAF for rx_kref of j1939_priv

It will trigger UAF for rx_kref of j1939_priv as following.

    cpu0                                    cpu1

j1939_sk_bind(socket0, ndev0, ...) j1939_netdev_start j1939_sk_bind(socket1, ndev0, ...) j1939_netdev_start j1939_priv_set j1939_priv_get_by_ndev_locked j1939_jsk_add ..... j1939_netdev_stop kref_put_lock(&priv->rx_kref, ...) kref_get(&priv->rx_kref, ...) REFCOUNT_WARN("addition on 0;...")

==================================================== refcount_t: addition on 0; use-after-free. WARNING: CPU: 1 PID: 20874 at lib/refcount.c:25 refcount_warn_saturate+0x169/0x1e0 RIP: 0010:refcount_warn_saturate+0x169/0x1e0 Call Trace: j1939_netdev_start+0x68b/0x920 j1939_sk_bind+0x426/0xeb0 ? security_socket_bind+0x83/0xb0

The rx_kref's kref_get() and kref_put() should use j1939_netdev_lock to protect.

CVSS Scores

version 3.1