In the Linux kernel, the following vulnerability has been resolved: fsdax: dax_unshare_iter needs to copy entire blocks The code that copies data from srcmap to iomap in dax_unshare_iter is very very broken, which bfoster's recent fsx changes have exposed. If the pos and len passed to dax_file_unshare are not aligned to an fsblock boundary, the iter pos and length in the _iter function will reflect this unalignment. dax_iomap_direct_access always returns a pointer to the start of the kmapped fsdax page, even if its pos argument is in the middle of that page. This is catastrophic for data integrity when iter->pos is not aligned to a page, because daddr/saddr do not point to the same byte in the file as iter->pos. Hence we corrupt user data by copying it to the wrong place. If iter->pos + iomap_length() in the _iter function not aligned to a page, then we fail to copy a full block, and only partially populate the destination block. This is catastrophic for data confidentiality because we expose stale pmem contents. Fix both of these issues by aligning copy_pos/copy_len to a page boundary (remember, this is fsdax so 1 fsblock == 1 base page) so that we always copy full blocks. We're not done yet -- there's no call to invalidate_inode_pages2_range, so programs that have the file range mmap'd will continue accessing the old memory mapping after the file metadata updates have completed. Be careful with the return value -- if the unshare succeeds, we still need to return the number of bytes that the iomap iter thinks we're operating on.

The remote Debian 12 host has packages installed that are affected by multiple vulnerabilities as referenced in the dsa-5818 advisory.

    - -------------------------------------------------------------------------     Debian Security Advisory DSA-5818-1                   security@debian.org     https://www.debian.org/security/                     Salvatore Bonaccorso     November 24, 2024                     https://www.debian.org/security/faq
    - -------------------------------------------------------------------------

    Package        : linux     CVE ID         : CVE-2022-45888 CVE-2023-52812 CVE-2024-26952 CVE-2024-26954                      CVE-2024-35964 CVE-2024-36244 CVE-2024-36478 CVE-2024-36914                      CVE-2024-36915 CVE-2024-36923 CVE-2024-38540 CVE-2024-38553                      CVE-2024-41080 CVE-2024-42322 CVE-2024-43868 CVE-2024-43904                      CVE-2024-43911 CVE-2024-44949 CVE-2024-49950 CVE-2024-49960                      CVE-2024-49974 CVE-2024-49986 CVE-2024-49991 CVE-2024-50012                      CVE-2024-50036 CVE-2024-50067 CVE-2024-50072 CVE-2024-50126                      CVE-2024-50215 CVE-2024-50218 CVE-2024-50228 CVE-2024-50229                      CVE-2024-50230 CVE-2024-50232 CVE-2024-50233 CVE-2024-50234                      CVE-2024-50235 CVE-2024-50236 CVE-2024-50237 CVE-2024-50242                      CVE-2024-50243 CVE-2024-50244 CVE-2024-50245 CVE-2024-50247                      CVE-2024-50249 CVE-2024-50250 CVE-2024-50251 CVE-2024-50252                      CVE-2024-50255 CVE-2024-50256 CVE-2024-50257 CVE-2024-50259                      CVE-2024-50261 CVE-2024-50262 CVE-2024-50264 CVE-2024-50265                      CVE-2024-50267 CVE-2024-50268 CVE-2024-50269 CVE-2024-50271                      CVE-2024-50272 CVE-2024-50273 CVE-2024-50276 CVE-2024-50278                      CVE-2024-50279 CVE-2024-50280 CVE-2024-50282 CVE-2024-50283                      CVE-2024-50284 CVE-2024-50286 CVE-2024-50287 CVE-2024-50290                      CVE-2024-50292 CVE-2024-50295 CVE-2024-50296 CVE-2024-50299                      CVE-2024-50301 CVE-2024-50302 CVE-2024-53042 CVE-2024-53043                      CVE-2024-53052 CVE-2024-53054 CVE-2024-53055 CVE-2024-53057                      CVE-2024-53058 CVE-2024-53059 CVE-2024-53060 CVE-2024-53061                      CVE-2024-53063 CVE-2024-53066 CVE-2024-53070 CVE-2024-53072                      CVE-2024-53081 CVE-2024-53082 CVE-2024-53088 CVE-2024-53093

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

    For the stable distribution (bookworm), these problems have been fixed in     version 6.1.119-1.

    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: debian-security-announce@lists.debian.org

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

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

Detections

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CVE-2024-50250

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Tenable Plugins

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