CVE-2024-50250

Aliases:UBUNTU-CVE-2024-50250DEBIAN-CVE-2024-50250
Advisory lineage Upstream: 0 Downstream: 40
Modified
Published: 09 Nov 2024, 10:14
Last modified:05 Aug 2026, 11:42

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (cve.org)
EPSS Score
0.23% LOW
0% probability +0.21%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

09 Nov 2024, 10:14
Published
Vulnerability first disclosed
05 Aug 2026, 11:42
Last Modified
Vulnerability information updated

Description

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.

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
  • v3.1•HIGH•Score: 7.1CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

EPSS Trends

Current EPSS score: 0.23%• Percentile: 14%

Affected Systems

  • debian•linux

    < 6.1.119-1 | < 6.11.7-1 | < 6.11.7-1

  • debian•linux-6.1

    < 6.1.119-1~deb11u1

  • ubuntu•linux

    < 6.8.0-58.60

  • ubuntu•linux-allwinner-5.19

    all

  • ubuntu•linux-aws

    < 6.8.0-1027.29

  • ubuntu•linux-aws-5.0

    all

  • ubuntu•linux-aws-5.11

    all

  • ubuntu•linux-aws-5.13

    all

  • ubuntu•linux-aws-5.19

    all

  • ubuntu•linux-aws-5.3

    all

  • ubuntu•linux-aws-5.8

    all

  • ubuntu•linux-aws-6.2

    all

  • ubuntu•linux-aws-6.5

    all

  • ubuntu•linux-aws-6.8

    < 6.8.0-1027.29~22.04.1

  • ubuntu•linux-azure

    all | < 6.8.0-1027.32

  • ubuntu•linux-azure-5.11

    all

  • ubuntu•linux-azure-5.13

    all

  • ubuntu•linux-azure-5.19

    all

  • ubuntu•linux-azure-5.3

    all

  • ubuntu•linux-azure-5.8

    all

  • ubuntu•linux-azure-6.11

    < 6.11.0-1012.12~24.04.1

  • ubuntu•linux-azure-6.2

    all

  • ubuntu•linux-azure-6.5

    all

  • ubuntu•linux-azure-6.8

    < 6.8.0-1027.32~22.04.1

  • ubuntu•linux-azure-edge

    all

  • ubuntu•linux-azure-fde

    all

  • ubuntu•linux-azure-fde-5.19

    all

  • ubuntu•linux-azure-fde-6.2

    all

  • ubuntu•linux-azure-nvidia

    < 6.8.0-1014.15

  • ubuntu•linux-fips

    < 6.8.0-78.78+fips1

  • ubuntu•linux-gcp

    all | < 6.8.0-1028.30

  • ubuntu•linux-gcp-5.11

    all

  • ubuntu•linux-gcp-5.13

    all

  • ubuntu•linux-gcp-5.19

    all

  • ubuntu•linux-gcp-5.3

    all

  • ubuntu•linux-gcp-5.8

    all

  • ubuntu•linux-gcp-6.11

    < 6.11.0-1011.11~24.04.1

  • ubuntu•linux-gcp-6.2

    all

  • ubuntu•linux-gcp-6.5

    all

  • ubuntu•linux-gcp-6.8

    < 6.8.0-1028.30~22.04.1

  • ubuntu•linux-gke

    all | < 6.8.0-1023.27

  • ubuntu•linux-gke-4.15

    all

  • ubuntu•linux-gke-5.15

    all

  • ubuntu•linux-gke-5.4

    all

  • ubuntu•linux-gkeop

    < 6.8.0-1010.12

  • ubuntu•linux-gkeop-5.4

    all

  • ubuntu•linux-hwe

    all

  • ubuntu•linux-hwe-5.11

    all

  • ubuntu•linux-hwe-5.13

    all

  • ubuntu•linux-hwe-5.19

    all

Showing first 50 affected entries in server-rendered view.

References (21)