In the Linux kernel, the following vulnerability has been resolved: mm/damon/dbgfs: protect targets destructions with kdamond_lock DAMON debugfs interface iterates current monitoring targets in 'dbgfs_target_ids_read()' while holding the corresponding 'kdamond_lock'. However, it also destructs the monitoring targets in 'dbgfs_before_terminate()' without holding the lock. This can result in a use_after_free bug. This commit avoids the race by protecting the destruction with the corresponding 'kdamond_lock'.

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: mm/damon/dbgfs: protect targets     destructions with kdamond_lock DAMON debugfs interface iterates current monitoring targets in     'dbgfs_target_ids_read()' while holding the corresponding 'kdamond_lock'. However, it also destructs the     monitoring targets in 'dbgfs_before_terminate()' without holding the lock. This can result in a     use_after_free bug. This commit avoids the race by protecting the destruction with the corresponding     'kdamond_lock'. (CVE-2021-47088)

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 5.10.106-102.504. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.10-2022-012 advisory.

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

    mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()' (CVE-2021-46937)

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

    mm/damon/dbgfs: protect targets destructions with kdamond_lock (CVE-2021-47088)

    A flaw was found in unrestricted eBPF usage by the BPF_BTF_LOAD, leading to a possible out-of-bounds     memory write in the Linux kernel's BPF subsystem due to the way a user loads BTF. This flaw allows a local     user to crash or escalate their privileges on the system. (CVE-2022-0500)

    A use-after-free flaw was found in the Linux kernel's FUSE filesystem in the way a user triggers write().
    This flaw allows a local user to gain unauthorized access to data from the FUSE filesystem, resulting in     privilege escalation. (CVE-2022-1011)

    A flaw was found in the Linux kernel in linux/net/netfilter/nf_tables_api.c of the netfilter subsystem.
    This flaw allows a local user to cause an out-of-bounds write issue. (CVE-2022-1015)

    A flaw was found in the Linux kernel in net/netfilter/nf_tables_core.c:nft_do_chain, which can cause a     use-after-free. This issue needs to handle return with proper preconditions, as it can lead to a kernel     information leak problem caused by a local, unprivileged attacker. (CVE-2022-1016)

    Linux PV device frontends vulnerable to attacks by backends T[his CNA information record relates to     multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Several Linux PV     device frontends are using the grant table interfaces for removing access rights of the backends in ways     being subject to race conditions, resulting in potential data leaks, data corruption by malicious     backends, and denial of service triggered by malicious backends: blkfront, netfront, scsifront and the     gntalloc driver are testing whether a grant reference is still in use. If this is not the case, they     assume that a following removal of the granted access will always succeed, which is not true in case the     backend has mapped the granted page between those two operations. As a result the backend can keep access     to the memory page of the guest no matter how the page will be used after the frontend I/O has finished.
    The xenbus driver has a similar problem, as it doesn't check the success of removing the granted access of     a shared ring buffer. blkfront: CVE-2022-23036 netfront: CVE-2022-23037 scsifront: CVE-2022-23038     gntalloc: CVE-2022-23039 xenbus: CVE-2022-23040 blkfront, netfront, scsifront, usbfront, dmabuf, xenbus,     9p, kbdfront, and pvcalls are using a functionality to delay freeing a grant reference until it is no     longer in use, but the freeing of the related data page is not synchronized with dropping the granted     access. As a result the backend can keep access to the memory page even after it has been freed and then     re-used for a different purpose. CVE-2022-23041 netfront will fail a BUG_ON() assertion if it fails to     revoke access in the rx path. This will result in a Denial of Service (DoS) situation of the guest which     can be triggered by the backend. CVE-2022-23042 (CVE-2022-23036)

    Linux PV device frontends vulnerable to attacks by backends T[his CNA information record relates to     multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Several Linux PV     device frontends are using the grant table interfaces for removing access rights of the backends in ways     being subject to race conditions, resulting in potential data leaks, data corruption by malicious     backends, and denial of service triggered by malicious backends: blkfront, netfront, scsifront and the     gntalloc driver are testing whether a grant reference is still in use. If this is not the case, they     assume that a following removal of the granted access will always succeed, which is not true in case the     backend has mapped the granted page between those two operations. As a result the backend can keep access     to the memory page of the guest no matter how the page will be used after the frontend I/O has finished.
    The xenbus driver has a similar problem, as it doesn't check the success of removing the granted access of     a shared ring buffer. blkfront: CVE-2022-23036 netfront: CVE-2022-23037 scsifront: CVE-2022-23038     gntalloc: CVE-2022-23039 xenbus: CVE-2022-23040 blkfront, netfront, scsifront, usbfront, dmabuf, xenbus,     9p, kbdfront, and pvcalls are using a functionality to delay freeing a grant reference until it is no     longer in use, but the freeing of the related data page is not synchronized with dropping the granted     access. As a result the backend can keep access to the memory page even after it has been freed and then     re-used for a different purpose. CVE-2022-23041 netfront will fail a BUG_ON() assertion if it fails to     revoke access in the rx path. This will result in a Denial of Service (DoS) situation of the guest which     can be triggered by the backend. CVE-2022-23042 (CVE-2022-23037)

    Linux PV device frontends vulnerable to attacks by backends T[his CNA information record relates to     multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Several Linux PV     device frontends are using the grant table interfaces for removing access rights of the backends in ways     being subject to race conditions, resulting in potential data leaks, data corruption by malicious     backends, and denial of service triggered by malicious backends: blkfront, netfront, scsifront and the     gntalloc driver are testing whether a grant reference is still in use. If this is not the case, they     assume that a following removal of the granted access will always succeed, which is not true in case the     backend has mapped the granted page between those two operations. As a result the backend can keep access     to the memory page of the guest no matter how the page will be used after the frontend I/O has finished.
    The xenbus driver has a similar problem, as it doesn't check the success of removing the granted access of     a shared ring buffer. blkfront: CVE-2022-23036 netfront: CVE-2022-23037 scsifront: CVE-2022-23038     gntalloc: CVE-2022-23039 xenbus: CVE-2022-23040 blkfront, netfront, scsifront, usbfront, dmabuf, xenbus,     9p, kbdfront, and pvcalls are using a functionality to delay freeing a grant reference until it is no     longer in use, but the freeing of the related data page is not synchronized with dropping the granted     access. As a result the backend can keep access to the memory page even after it has been freed and then     re-used for a different purpose. CVE-2022-23041 netfront will fail a BUG_ON() assertion if it fails to     revoke access in the rx path. This will result in a Denial of Service (DoS) situation of the guest which     can be triggered by the backend. CVE-2022-23042 (CVE-2022-23038)

    Linux PV device frontends vulnerable to attacks by backends T[his CNA information record relates to     multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Several Linux PV     device frontends are using the grant table interfaces for removing access rights of the backends in ways     being subject to race conditions, resulting in potential data leaks, data corruption by malicious     backends, and denial of service triggered by malicious backends: blkfront, netfront, scsifront and the     gntalloc driver are testing whether a grant reference is still in use. If this is not the case, they     assume that a following removal of the granted access will always succeed, which is not true in case the     backend has mapped the granted page between those two operations. As a result the backend can keep access     to the memory page of the guest no matter how the page will be used after the frontend I/O has finished.
    The xenbus driver has a similar problem, as it doesn't check the success of removing the granted access of     a shared ring buffer. blkfront: CVE-2022-23036 netfront: CVE-2022-23037 scsifront: CVE-2022-23038     gntalloc: CVE-2022-23039 xenbus: CVE-2022-23040 blkfront, netfront, scsifront, usbfront, dmabuf, xenbus,     9p, kbdfront, and pvcalls are using a functionality to delay freeing a grant reference until it is no     longer in use, but the freeing of the related data page is not synchronized with dropping the granted     access. As a result the backend can keep access to the memory page even after it has been freed and then     re-used for a different purpose. CVE-2022-23041 netfront will fail a BUG_ON() assertion if it fails to     revoke access in the rx path. This will result in a Denial of Service (DoS) situation of the guest which     can be triggered by the backend. CVE-2022-23042 (CVE-2022-23039)

    Linux PV device frontends vulnerable to attacks by backends T[his CNA information record relates to     multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Several Linux PV     device frontends are using the grant table interfaces for removing access rights of the backends in ways     being subject to race conditions, resulting in potential data leaks, data corruption by malicious     backends, and denial of service triggered by malicious backends: blkfront, netfront, scsifront and the     gntalloc driver are testing whether a grant reference is still in use. If this is not the case, they     assume that a following removal of the granted access will always succeed, which is not true in case the     backend has mapped the granted page between those two operations. As a result the backend can keep access     to the memory page of the guest no matter how the page will be used after the frontend I/O has finished.
    The xenbus driver has a similar problem, as it doesn't check the success of removing the granted access of     a shared ring buffer. blkfront: CVE-2022-23036 netfront: CVE-2022-23037 scsifront: CVE-2022-23038     gntalloc: CVE-2022-23039 xenbus: CVE-2022-23040 blkfront, netfront, scsifront, usbfront, dmabuf, xenbus,     9p, kbdfront, and pvcalls are using a functionality to delay freeing a grant reference until it is no     longer in use, but the freeing of the related data page is not synchronized with dropping the granted     access. As a result the backend can keep access to the memory page even after it has been freed and then     re-used for a different purpose. CVE-2022-23041 netfront will fail a BUG_ON() assertion if it fails to     revoke access in the rx path. This will result in a Denial of Service (DoS) situation of the guest which     can be triggered by the backend. CVE-2022-23042 (CVE-2022-23040)

    Linux PV device frontends vulnerable to attacks by backends T[his CNA information record relates to     multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] Several Linux PV     device frontends are using the grant table interfaces for removing access rights of the backends in ways     being subject to race conditions, resulting in potential data leaks, data corruption by malicious     backends, and denial of service triggered by malicious backends: blkfront, netfront, scsifront and the     gntalloc driver are testing whether a grant reference is still in use. If this is not the case, they     assume that a following removal of the granted access will always succeed, which is not true in case the     backend has mapped the granted page between those two operations. As a result the backend can keep access     to the memory page of the guest no matter how the page will be used after the frontend I/O has finished.
    The xenbus driver has a similar problem, as it doesn't check the success of removing the granted access of     a shared ring buffer. blkfront: CVE-2022-23036 netfront: CVE-2022-23037 scsifront: CVE-2022-23038     gntalloc: CVE-2022-23039 xenbus: CVE-2022-23040 blkfront, netfront, scsifront, usbfront, dmabuf, xenbus,     9p, kbdfront, and pvcalls are using a functionality to delay freeing a grant reference until it is no     longer in use, but the freeing of the related data page is not synchronized with dropping the granted     access. As a result the backend can keep access to the memory page even after it has been freed and then     re-used for a different purpose. CVE-2022-23041 netfront will fail a BUG_ON() assertion if it fails to     revoke access in the rx path. This will result in a Denial of Service (DoS) situation of the guest which     can be triggered by the backend. CVE-2022-23042 (CVE-2022-23042)

    The Amazon Linux kernel now enables, by default, a software mitigation for this issue, on all ARM-based     EC2 instance types. (CVE-2022-23960)

    An out-of-bounds (OOB) memory access flaw was found in nft_fwd_dup_netdev_offload in     net/netfilter/nf_dup_netdev.c in the netfilter subcomponent in the Linux kernel due to a heap out-of-     bounds write problem. This flaw allows a local attacker with a user account on the system to gain access     to out-of-bounds memory, leading to a system crash or a privilege escalation threat. (CVE-2022-25636)

    A heap buffer overflow flaw was found in IPsec ESP transformation code in net/ipv4/esp4.c and     net/ipv6/esp6.c. This flaw allows a local attacker with a normal user privilege to overwrite kernel heap     objects and may cause a local privilege escalation threat. (CVE-2022-27666)

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

    watch_queue: Fix filter limit check (CVE-2022-48847)

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

    net-sysfs: add check for netdevice being present to speed_show (CVE-2022-48850)

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

    sctp: fix kernel-infoleak for SCTP sockets (CVE-2022-48855)

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

    net/mlx5: Fix a race on command flush flow (CVE-2022-48858)

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

    tipc: fix kernel panic when enabling bearer (CVE-2022-48865)

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

    netfilter: nf_queue: fix possible use-after-free (CVE-2022-48911)

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

    netfilter: fix use-after-free in __nf_register_net_hook() (CVE-2022-48912)

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

    cifs: fix double free race when mount fails in cifs_get_root() (CVE-2022-48919)

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

    RDMA/cma: Do not change route.addr.src_addr outside state checks (CVE-2022-48925)

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

    KVM: x86/mmu: make apf token non-zero to fix bug (CVE-2022-48943)

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

    netfilter: nf_tables: initialize registers in nft_do_chain() (CVE-2022-49293)

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.

The version of kernel installed on the remote host is prior to 5.4.186-102.354. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2KERNEL-5.4-2022-024 advisory.

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

    mm/damon/dbgfs: fix 'struct pid' leaks in 'dbgfs_target_ids_write()' (CVE-2021-46937)

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

    mm/damon/dbgfs: protect targets destructions with kdamond_lock (CVE-2021-47088)

    A flaw was found in the Linux kernel in linux/net/netfilter/nf_tables_api.c of the netfilter subsystem.
    This flaw allows a local user to cause an out-of-bounds write issue. (CVE-2022-1015)

    A flaw was found in the Linux kernel in net/netfilter/nf_tables_core.c:nft_do_chain, which can cause a     use-after-free. This issue needs to handle return with proper preconditions, as it can lead to a kernel     information leak problem caused by a local, unprivileged attacker. (CVE-2022-1016)

    A use-after-free vulnerability was found in the tc_new_tfilter function in net/sched/cls_api.c in the     Linux kernel. The availability of local, unprivileged user namespaces allows privilege escalation.
    (CVE-2022-1055)

    An out-of-bounds (OOB) memory access flaw was found in nft_fwd_dup_netdev_offload in     net/netfilter/nf_dup_netdev.c in the netfilter subcomponent in the Linux kernel due to a heap out-of-     bounds write problem. This flaw allows a local attacker with a user account on the system to gain access     to out-of-bounds memory, leading to a system crash or a privilege escalation threat. (CVE-2022-25636)

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

    drm/vrr: Set VRR capable prop only if it is attached to connector (CVE-2022-48843)

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

    net-sysfs: add check for netdevice being present to speed_show (CVE-2022-48850)

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

    sctp: fix kernel-infoleak for SCTP sockets (CVE-2022-48855)

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

    net/mlx5: Fix a race on command flush flow (CVE-2022-48858)

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

    netfilter: nf_queue: fix possible use-after-free (CVE-2022-48911)

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

    netfilter: fix use-after-free in __nf_register_net_hook() (CVE-2022-48912)

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

    cifs: fix double free race when mount fails in cifs_get_root() (CVE-2022-48919)

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

    netfilter: nf_tables: initialize registers in nft_do_chain() (CVE-2022-49293)

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
248031	Linux Distros Unpatched Vulnerability : CVE-2021-47088	Nessus	Misc.	high
160433	Amazon Linux 2 : kernel (ALASKERNEL-5.10-2022-012)	Nessus	Amazon Linux Local Security Checks	high
160422	Amazon Linux 2 : kernel (ALASKERNEL-5.4-2022-024)	Nessus	Amazon Linux Local Security Checks	high

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