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Debian Security Advisory DSA-4978-1                   [email protected]
https://www.debian.org/security/                     Salvatore Bonaccorso
September 25, 2021                    https://www.debian.org/security/faq
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Package        : linux
CVE ID         : CVE-2020-3702 CVE-2020-16119 CVE-2021-3653 CVE-2021-3656 
                 CVE-2021-3679 CVE-2021-3732 CVE-2021-3739 CVE-2021-3743 
                 CVE-2021-3753 CVE-2021-37576 CVE-2021-38160 CVE-2021-38166 
                 CVE-2021-38199 CVE-2021-40490 CVE-2021-41073
Debian Bug     : 993948 993978

Several vulnerabilities have been discovered in the Linux kernel
that may lead to a privilege escalation, denial of service or
information leaks.

CVE-2020-3702

    A flaw was found in the driver for Atheros IEEE 802.11n family of
    chipsets (ath9k) allowing information disclosure.

CVE-2020-16119

    Hadar Manor reported a use-after-free in the DCCP protocol
    implementation in the Linux kernel. A local attacker can take
    advantage of this flaw to cause a denial of service or potentially
    to execute arbitrary code.

CVE-2021-3653

    Maxim Levitsky discovered a vulnerability in the KVM hypervisor
    implementation for AMD processors in the Linux kernel: Missing
    validation of the `int_ctl` VMCB field could allow a malicious L1
    guest to enable AVIC support (Advanced Virtual Interrupt Controller)
    for the L2 guest. The L2 guest can take advantage of this flaw to
    write to a limited but still relatively large subset of the host
    physical memory.

CVE-2021-3656

    Maxim Levitsky and Paolo Bonzini discovered a flaw in the KVM
    hypervisor implementation for AMD processors in the Linux kernel.
    Missing validation of the the `virt_ext` VMCB field could allow a
    malicious L1 guest to disable both VMLOAD/VMSAVE intercepts and VLS
    (Virtual VMLOAD/VMSAVE) for the L2 guest. Under these circumstances,
    the L2 guest is able to run VMLOAD/VMSAVE unintercepted and thus
    read/write portions of the host's physical memory.

CVE-2021-3679

    A flaw in the Linux kernel tracing module functionality could allow
    a privileged local user (with CAP_SYS_ADMIN capability) to cause a
    denial of service (resource starvation).

CVE-2021-3732

    Alois Wohlschlager reported a flaw in the implementation of the
    overlayfs subsystem, allowing a local attacker with privileges to
    mount a filesystem to reveal files hidden in the original mount.

CVE-2021-3739

    A NULL pointer dereference flaw was found in the btrfs filesystem,
    allowing a local attacker with CAP_SYS_ADMIN capabilities to cause a
    denial of service.

CVE-2021-3743

    An out-of-bounds memory read was discovered in the Qualcomm IPC
    router protocol implementation, allowing to cause a denial of
    service or information leak.

CVE-2021-3753

    Minh Yuan reported a race condition in the vt_k_ioctl in
    drivers/tty/vt/vt_ioctl.c, which may cause an out of bounds
    read in vt.

CVE-2021-37576

    Alexey Kardashevskiy reported a buffer overflow in the KVM subsystem
    on the powerpc platform, which allows KVM guest OS users to cause
    memory corruption on the host.

CVE-2021-38160

    A flaw in the virtio_console was discovered allowing data corruption
    or data loss by an untrusted device.

CVE-2021-38166

    An integer overflow flaw in the BPF subsystem could allow a local
    attacker to cause a denial of service or potentially the execution
    of arbitrary code. This flaw is mitigated by default in Debian as
    unprivileged calls to bpf() are disabled.

CVE-2021-38199

    Michael Wakabayashi reported a flaw in the NFSv4 client
    implementation, where incorrect connection setup ordering allows
    operations of a remote NFSv4 server to cause a denial of service.

CVE-2021-40490

    A race condition was discovered in the ext4 subsystem when writing
    to an inline_data file while its xattrs are changing. This could
    result in denial of service.

CVE-2021-41073

    Valentina Palmiotti discovered a flaw in io_uring allowing a local
    attacker to escalate privileges.

For the stable distribution (bullseye), these problems have been fixed in
version 5.10.46-5. This update includes fixes for #993948 and #993978.

We recommend that you upgrade your linux packages.

For the detailed security status of linux please refer to
its security tracker page at:
https://security-tracker.debian.org/tracker/linux

Further information about Debian Security Advisories, how to apply
these updates to your system and frequently asked questions can be
found at: https://www.debian.org/security/

Mailing list: [email protected]