CVE-2022-49075

MEDIUM EPSS 14.1%
Published Feb 26, 20251y ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Feb 26, 2025 1y ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix qgroup reserve overflow the qgroup limit We use extent_changeset->bytes_changed in qgroup_reserve_data() to record how many bytes we set for EXTENT_QGROUP_RESERVED state. Currently the bytes_changed is set as "unsigned int", and it will overflow if we try to fallocate a range larger than 4GiB. The result is we reserve less bytes and eventually break the qgroup limit. Unlike regular buffered/direct write, which we use one changeset for each ordered extent, which can never be larger than 256M. For fallocate, we use one changeset for the whole range, thus it no longer respects the 256M per extent limit, and caused the problem. The following example test script reproduces the problem: $ cat qgroup-overflow.sh #!/bin/bash DEV=/dev/sdj MNT=/mnt/sdj mkfs.btrfs -f $DEV mount $DEV $MNT # Set qgroup limit to 2GiB. btrfs quota enable $MNT btrfs qgroup limit 2G $MNT # Try to fallocate a 3GiB file. This should fail. echo echo "Try to fallocate a 3GiB file..." fallocate -l 3G $MNT/3G.file # Try to fallocate a 5GiB file. echo echo "Try to fallocate a 5GiB file..." fallocate -l 5G $MNT/5G.file # See we break the qgroup limit. echo sync btrfs qgroup show -r $MNT umount $MNT When running the test: $ ./qgroup-overflow.sh (...) Try to fallocate a 3GiB file... fallocate: fallocate failed: Disk quota exceeded Try to fallocate a 5GiB file... qgroupid         rfer         excl     max_rfer --------         ----         ----     -------- 0/5           5.00GiB      5.00GiB      2.00GiB Since we have no control of how bytes_changed is used, it's better to set it to u64.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
14.1% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-190 Integer Overflow or Wraparound Numeric Error

Affected Products 8

VendorProductVersionRange
linuxlinux_kernel* <4.14.276
linuxlinux_kernel*≥4.15  –  <4.19.238
linuxlinux_kernel*≥4.20  –  <5.4.189
linuxlinux_kernel*≥5.5  –  <5.10.111
linuxlinux_kernel*≥5.11  –  <5.15.34
linuxlinux_kernel*≥5.16  –  <5.16.20
linuxlinux_kernel*≥5.17  –  <5.17.3
linuxlinux_kernel5.18any

References 8

  • git.kernel.org https://git.kernel.org/stable/c/0355387ea5b02d353c9415613fab908fac5c52a6
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/44277c50fdba5019ca25bfad1b71e2561b0de11b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/4b98799e181b4326a613108cf37acc1f55d21b45
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6bfff81286d4491f02dad7814bae5c77c9ad2320
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7941b74ed49b6db25efbef2256ebef843c11a010
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/82ae73ac963cee877ce34f7c31b2b456b516e96c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b642b52d0b50f4d398cb4293f64992d0eed2e2ce
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f3d97b22a708bf9e3f3ac2ba232bcefd0b0c136b
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/0355387ea5b02d353c9415613fab908fac5c52a6
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/44277c50fdba5019ca25bfad1b71e2561b0de11b
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/4b98799e181b4326a613108cf37acc1f55d21b45
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/6bfff81286d4491f02dad7814bae5c77c9ad2320
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/7941b74ed49b6db25efbef2256ebef843c11a010
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/82ae73ac963cee877ce34f7c31b2b456b516e96c
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/b642b52d0b50f4d398cb4293f64992d0eed2e2ce
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f3d97b22a708bf9e3f3ac2ba232bcefd0b0c136b
    Patch