cbcvebase.
CVE-2022-49075
published 2025-02-26

CVE-2022-49075: In the Linux kernel, the following vulnerability has been resolved: btrfs: fix qgroup reserve overflow the qgroup limit We use extent_changeset->bytes_changed…

PriorityP423medium5.5CVSS 3.1
AVLACLPRLUINSUCNINAH
EPSS
0.65%
47.6th percentile
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.

Affected

22 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 5.17.3-1 (bookworm)linux 5.17.3-1 (bookworm)
linuxlinux——
linuxlinux>= 7bc329c1836866ffac8b2613f780a51b3ffe786d < 0355387ea5b02d353c9415613fab908fac5c52a60355387ea5b02d353c9415613fab908fac5c52a6
linuxlinux>= 7bc329c1836866ffac8b2613f780a51b3ffe786d < f3d97b22a708bf9e3f3ac2ba232bcefd0b0c136bf3d97b22a708bf9e3f3ac2ba232bcefd0b0c136b
linuxlinux>= 7bc329c1836866ffac8b2613f780a51b3ffe786d < 44277c50fdba5019ca25bfad1b71e2561b0de11b44277c50fdba5019ca25bfad1b71e2561b0de11b
linuxlinux>= 7bc329c1836866ffac8b2613f780a51b3ffe786d < 82ae73ac963cee877ce34f7c31b2b456b516e96c82ae73ac963cee877ce34f7c31b2b456b516e96c
linuxlinux>= 7bc329c1836866ffac8b2613f780a51b3ffe786d < 4b98799e181b4326a613108cf37acc1f55d21b454b98799e181b4326a613108cf37acc1f55d21b45
linuxlinux>= 7bc329c1836866ffac8b2613f780a51b3ffe786d < 6bfff81286d4491f02dad7814bae5c77c9ad23206bfff81286d4491f02dad7814bae5c77c9ad2320
linuxlinux>= 7bc329c1836866ffac8b2613f780a51b3ffe786d < 7941b74ed49b6db25efbef2256ebef843c11a0107941b74ed49b6db25efbef2256ebef843c11a010
linuxlinux>= 7bc329c1836866ffac8b2613f780a51b3ffe786d < b642b52d0b50f4d398cb4293f64992d0eed2e2ceb642b52d0b50f4d398cb4293f64992d0eed2e2ce
linuxlinux_kernel< 4.14.2764.14.276
linuxlinux_kernel——
linuxlinux_kernel>= 0 < 5.10.113-15.10.113-1
linuxlinux_kernel>= 0 < 5.17.3-15.17.3-1
linuxlinux_kernel>= 0 < 5.17.3-15.17.3-1
linuxlinux_kernel>= 0 < 5.17.3-15.17.3-1
linuxlinux_kernel>= 4.15 < 4.19.2384.19.238
linuxlinux_kernel>= 4.20 < 5.4.1895.4.189
linuxlinux_kernel>= 5.11 < 5.15.345.15.34
linuxlinux_kernel>= 5.16 < 5.16.205.16.20
linuxlinux_kernel>= 5.17 < 5.17.35.17.3
linuxlinux_kernel>= 5.5 < 5.10.1115.10.111

CVSS provenance

nvdv3.15.5MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
osv5.5MEDIUM
vendor_debian5.5MEDIUM
vendor_redhat5.5MEDIUM
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