In the Linux kernel, the following vulnerability has been resolved: sched/core: Fix use-after-free bug in dup_user_cpus_ptr() Since commit 07ec77a1d4e8 ("sched: Allow task CPU affinity to be restricted on asymmetric systems"), the setting and clearing of user_cpus_ptr are done under pi_lock for arm64 architecture. However, dup_user_cpus_ptr() accesses user_cpus_ptr without any lock protection. Since sched_setaffinity() can be invoked from another process, the process being modified may be undergoing fork() at the same time. When racing with the clearing of user_cpus_ptr in __set_cpus_allowed_ptr_locked(), it can lead to user-after-free and possibly double-free in arm64 kernel. Commit 8f9ea86fdf99 ("sched: Always preserve the user requested cpumask") fixes this problem as user_cpus_ptr, once set, will never be cleared in a task's lifetime. However, this bug was re-introduced in commit 851a723e45d1 ("sched: Always clear user_cpus_ptr in do_set_cpus_allowed()") which allows the clearing of user_cpus_ptr in do_set_cpus_allowed(). This time, it will affect all arches. Fix this bug by always clearing the user_cpus_ptr of the newly cloned/forked task before the copying process starts and check the user_cpus_ptr state of the source task under pi_lock. Note to stable, this patch won't be applicable to stable releases. Just copy the new dup_user_cpus_ptr() function over.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - In the Linux kernel, the following vulnerability has been resolved: sched/core: Fix use-after-free bug in     dup_user_cpus_ptr() Since commit 07ec77a1d4e8 (sched: Allow task CPU affinity to be restricted on     asymmetric systems), the setting and clearing of user_cpus_ptr are done under pi_lock for arm64     architecture. However, dup_user_cpus_ptr() accesses user_cpus_ptr without any lock protection. Since     sched_setaffinity() can be invoked from another process, the process being modified may be undergoing     fork() at the same time. When racing with the clearing of user_cpus_ptr in
    __set_cpus_allowed_ptr_locked(), it can lead to user-after-free and possibly double-free in arm64 kernel.
    Commit 8f9ea86fdf99 (sched: Always preserve the user requested cpumask) fixes this problem as     user_cpus_ptr, once set, will never be cleared in a task's lifetime. However, this bug was re-introduced     in commit 851a723e45d1 (sched: Always clear user_cpus_ptr in do_set_cpus_allowed()) which allows the     clearing of user_cpus_ptr in do_set_cpus_allowed(). This time, it will affect all arches. Fix this bug by     always clearing the user_cpus_ptr of the newly cloned/forked task before the copying process starts and     check the user_cpus_ptr state of the source task under pi_lock. Note to stable, this patch won't be     applicable to stable releases. Just copy the new dup_user_cpus_ptr() function over. (CVE-2022-48892)

Note that Nessus relies on the presence of the package as reported by the vendor.

The version of kernel installed on the remote host is prior to 5.15.90-54.138. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.15-2023-013 advisory.

    In the Linux kernel before 6.1.6, a NULL pointer dereference bug in the traffic control subsystem allows     an unprivileged user to trigger a denial of service (system crash) via a crafted traffic control     configuration that is set up with tc qdisc and tc class commands. This affects qdisc_graft in     net/sched/sch_api.c. (CVE-2022-47929)

    A flaw NULL Pointer Dereference in the Linux kernel NTFS3 driver function attr_punch_hole() was found. A     local user could use this flaw to crash the system. (CVE-2022-4842)

    In the Linux kernel before 6.1.3, fs/ntfs3/inode.c does not validate the attribute name offset. An     unhandled page fault may occur. (CVE-2022-48424)

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

    sched/core: Fix use-after-free bug in dup_user_cpus_ptr() (CVE-2022-48892)

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

    pnode: terminate at peers of source (CVE-2022-50280)

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

    ext4: fix potential out of bound read in ext4_fc_replay_scan() (CVE-2022-50306)

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

    cifs: fix oops during encryption (CVE-2022-50341)

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

    ext4: init quota for 'old.inode' in 'ext4_rename' (CVE-2022-50346)

    The Linux kernel does not correctly mitigate SMT attacks, as discovered through a strange pattern in the     kernel API using STIBP as a mitigation, leaving the process exposed for a short period of time after a     syscall. The kernel also does not issue an IBPB immediately during the syscall. (CVE-2023-0045)

    A buffer overflow vulnerability was found in the Netfilter subsystem in the Linux Kernel. This issue could     allow the leakage of both stack and heap addresses, and potentially allow Local Privilege Escalation to     the root user via arbitrary code execution. (CVE-2023-0179)

    A NULL pointer dereference flaw was found in rawv6_push_pending_frames in net/ipv6/raw.c in the network     subcomponent in the Linux kernel. This flaw causes the system to crash. (CVE-2023-0394)

    Detected a few exploitable gadgets that could leak secret memory through a side-channel such as MDS as     well as insufficient hardening of the usercopy functions against spectre-v1. (CVE-2023-0459)

    There is a use-after-free vulnerability in the Linux Kernel which can be exploited to achieve local     privilege escalation. To reach the vulnerability kernel configuration flag CONFIG_TLS or     CONFIG_XFRM_ESPINTCP has to be configured, but the operation does not require any privilege.

    There is a use-after-free bug of icsk_ulp_data of a struct inet_connection_sock.

    When CONFIG_TLS is enabled, user can install a tls context (struct tls_context) on a connected tcp socket.
    The context is not cleared if this socket is disconnected and reused as a listener. If a new socket is     created from the listener, the context is inherited and vulnerable.

    The setsockopt TCP_ULP operation does not require any privilege.

    We recommend upgrading past commit 2c02d41d71f90a5168391b6a5f2954112ba2307c (CVE-2023-0461)

    cbq_classify in net/sched/sch_cbq.c in the Linux kernel through 6.1.4 allows attackers to cause a denial     of service (slab-out-of-bounds read) because of type confusion (non-negative numbers can sometimes     indicate a TC_ACT_SHOT condition rather than valid classification results). (CVE-2023-23454)

    atm_tc_enqueue in net/sched/sch_atm.c in the Linux kernel through 6.1.4 allows attackers to cause a denial     of service because of type confusion (non-negative numbers can sometimes indicate a TC_ACT_SHOT condition     rather than valid classification results). (CVE-2023-23455)

    In the Linux kernel 6.0.8, there is a use-after-free in run_unpack in fs/ntfs3/run.c, related to a     difference between NTFS sector size and media sector size. (CVE-2023-26544)

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

    net/sched: act_mpls: Fix warning during failed attribute validation (CVE-2023-52906)

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

    netfilter: ipset: Fix overflow before widen in the bitmap_ip_create() function. (CVE-2023-53032)

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

    netfilter: nft_payload: incorrect arithmetics when fetching VLAN header bits (CVE-2023-53033)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
250226	Linux Distros Unpatched Vulnerability : CVE-2022-48892	Nessus	Misc.	high
171227	Amazon Linux 2 : kernel, --advisory ALAS2KERNEL-5.15-2023-013 (ALASKERNEL-5.15-2023-013)	Nessus	Amazon Linux Local Security Checks	high

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