OESA-2023-1636

The Linux Kernel, the operating system core itself.

Security Fix(es):

A flaw was found in the Linux kernel's ksmbd, a high-performance in-kernel SMB server. The specific flaw exists within the handling of SMB2SESSIONSETUP commands. The issue results from the lack of control of resource consumption. An attacker can leverage this vulnerability to create a denial-of-service condition on the system.(CVE-2023-32247)

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation.

When nftablesdelrule() is flushing table rules, it is not checked whether the chain is bound and the chain's owner rule can also release the objects in certain circumstances.

We recommend upgrading past commit 6eaf41e87a223ae6f8e7a28d6e78384ad7e407f8.

(CVE-2023-3777)

A use-after-free vulnerability in the Linux kernel's netfilter: nf_tables component can be exploited to achieve local privilege escalation.

On an error when building a nftables rule, deactivating immediate expressions in nftimmediatedeactivate() can lead unbinding the chain and objects be deactivated but later used.

We recommend upgrading past commit 0a771f7b266b02d262900c75f1e175c7fe76fec2.

(CVE-2023-4015)

A use-after-free vulnerability in the Linux kernel's net/sched: cls_route component can be exploited to achieve local privilege escalation.

When route4change() is called on an existing filter, the whole tcfresult struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcfunbindfilter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free.

We recommend upgrading past commit b80b829e9e2c1b3f7aae34855e04d8f6ecaf13c8.

(CVE-2023-4206)

A use-after-free vulnerability in the Linux kernel's net/sched: cls_fw component can be exploited to achieve local privilege escalation.

When fwchange() is called on an existing filter, the whole tcfresult struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcfunbindfilter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free.

We recommend upgrading past commit 76e42ae831991c828cffa8c37736ebfb831ad5ec.

(CVE-2023-4207)

A use-after-free vulnerability in the Linux kernel's net/sched: cls_u32 component can be exploited to achieve local privilege escalation.

When u32change() is called on an existing filter, the whole tcfresult struct is always copied into the new instance of the filter. This causes a problem when updating a filter bound to a class, as tcfunbindfilter() is always called on the old instance in the success path, decreasing filter_cnt of the still referenced class and allowing it to be deleted, leading to a use-after-free.

We recommend upgrading past commit 3044b16e7c6fe5d24b1cdbcf1bd0a9d92d1ebd81.

(CVE-2023-4208)

A use-after-free vulnerability in the Linux kernel's af_unix component can be exploited to achieve local privilege escalation.

The unixstreamsendpage() function tries to add data to the last skb in the peer's recv queue without locking the queue. Thus there is a race where unixstreamsendpage() could access an skb locklessly that is being released by garbage collection, resulting in use-after-free.

We recommend upgrading past commit 790c2f9d15b594350ae9bca7b236f2b1859de02c.

(CVE-2023-4622)