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Debian Security Advisory DSA-5050-1                   [email protected]
https://www.debian.org/security/                     Salvatore Bonaccorso
January 20, 2022                      https://www.debian.org/security/faq
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Package        : linux
CVE ID         : CVE-2021-4155 CVE-2021-28711 CVE-2021-28712 CVE-2021-28713
                 CVE-2021-28714 CVE-2021-28715 CVE-2021-39685 CVE-2021-45095
                 CVE-2021-45469 CVE-2021-45480 CVE-2022-0185 CVE-2022-23222
Debian Bug     : 988044 996974

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


    Kirill Tkhai discovered a data leak in the way the XFS_IOC_ALLOCSP
    IOCTL in the XFS filesystem allowed for a size increase of files
    with unaligned size. A local attacker can take advantage of this
    flaw to leak data on the XFS filesystem.

CVE-2021-28711, CVE-2021-28712, CVE-2021-28713 (XSA-391)

    Juergen Gross reported that malicious PV backends can cause a denial
    of service to guests being serviced by those backends via high
    frequency events, even if those backends are running in a less
    privileged environment.

CVE-2021-28714, CVE-2021-28715 (XSA-392)

    Juergen Gross discovered that Xen guests can force the Linux
    netback driver to hog large amounts of kernel memory, resulting in
    denial of service.


    Szymon Heidrich discovered a buffer overflow vulnerability in the
    USB gadget subsystem, resulting in information disclosure, denial of
    service or privilege escalation.


    It was discovered that the Phone Network protocol (PhoNet) driver
    has a reference count leak in the pep_sock_accept() function.


    Wenqing Liu reported an out-of-bounds memory access in the f2fs
    implementation if an inode has an invalid last xattr entry. An
    attacker able to mount a specially crafted image can take advantage
    of this flaw for denial of service.


    A memory leak flaw was discovered in the __rds_conn_create()
    function in the RDS (Reliable Datagram Sockets) protocol subsystem.


    William Liu, Jamie Hill-Daniel, Isaac Badipe, Alec Petridis, Hrvoje
    Misetic and Philip Papurt discovered a heap-based buffer overflow
    flaw in the legacy_parse_param function in the Filesystem Context
    functionality, allowing an local user (with CAP_SYS_ADMIN capability
    in the current namespace) to escalate privileges.


    'tr3e' discovered that the BPF verifier does not properly restrict
    several *_OR_NULL pointer types allowing these types to do pointer
    arithmetic. A local user with the ability to call bpf(), can take
    advantage of this flaw to excalate privileges. Unprivileged calls to
    bpf() are disabled by default in Debian, mitigating this flaw.

For the stable distribution (bullseye), these problems have been fixed in
version 5.10.92-1. This version includes changes which were aimed to
land in the next Debian bullseye point release.

We recommend that you upgrade your linux packages.

For the detailed security status of linux please refer to its security
tracker page at:

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]