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Vulnerability · Published Feb 26, 2025 · Assigned by Linux

CVE-2022-49068btrfs: release correct delalloc amount in direct IO write path

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 18% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.3%top 82.4% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: btrfs: release correct delalloc amount in direct IO write path Running generic/406 causes the following WARNING in btrfs_destroy_inode() which tells there are outstanding extents left. In btrfs_get_blocks_direct_write(), we reserve a temporary outstanding extents with btrfs_delalloc_reserve_metadata() (or indirectly from btrfs_delalloc_reserve_space(()). We then release the outstanding extents with btrfs_delalloc_release_extents(). However, the "len" can be modified in the COW case, which releases fewer outstanding extents than expected. Fix it by calling btrfs_delalloc_release_extents() for the original length. To reproduce the warning, the filesystem should be 1 GiB. It's triggering a short-write, due to not being able to allocate a large extent and instead allocating a smaller one. WARNING: CPU: 0 PID: 757 at fs/btrfs/inode.c:8848 btrfs_destroy_inode+0x1e6/0x210 [btrfs] Modules linked in: btrfs blake2b_generic xor lzo_compress lzo_decompress raid6_pq zstd zstd_decompress zstd_compress xxhash zram zsmalloc CPU: 0 PID: 757 Comm: umount Not tainted 5.17.0-rc8+ #101 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS d55cb5a 04/01/2014 RIP: 0010:btrfs_destroy_inode+0x1e6/0x210 [btrfs] RSP: 0018:ffffc9000327bda8 EFLAGS: 00010206 RAX: 0000000000000000 RBX: ffff888100548b78 RCX: 0000000000000000 RDX: 0000000000026900 RSI: 0000000000000000 RDI: ffff888100548b78 RBP: ffff888100548940 R08: 0000000000000000 R09: ffff88810b48aba8 R10: 0000000000000001 R11: ffff8881004eb240 R12: ffff88810b48a800 R13: ffff88810b48ec08 R14: ffff88810b48ed00 R15: ffff888100490c68 FS: 00007f8549ea0b80(0000) GS:ffff888237c00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f854a09e733 CR3: 000000010a2e9003 CR4: 0000000000370eb0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> destroy_inode+0x33/0x70 dispose_list+0x43/0x60 evict_inodes+0x161/0x1b0 generic_shutdown_super+0x2d/0x110 kill_anon_super+0xf/0x20 btrfs_kill_super+0xd/0x20 [btrfs] deactivate_locked_super+0x27/0x90 cleanup_mnt+0x12c/0x180 task_work_run+0x54/0x80 exit_to_user_mode_prepare+0x152/0x160 syscall_exit_to_user_mode+0x12/0x30 do_syscall_64+0x42/0x80 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f854a000fb7

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.17.6-1DEBIAN-CVE-2022-49068
Debian:13linux5.17.6-1DEBIAN-CVE-2022-49068
Debian:14linux5.17.6-1DEBIAN-CVE-2022-49068
Ubuntu:22.04:LTSlinux5.15.0-37.39UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-aws5.15.0-1011.14UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-azure5.15.0-1010.12UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-gcp5.15.0-1008.12UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-gke5.15.0-1008.10UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-ibm5.15.0-1007.8UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1008.11UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-kvm5.15.0-1010.11UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-37.39UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-oracle5.15.0-1009.12UBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-raspi5.15.0-1011.13UBUNTU-CVE-2022-49068
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2022-49068
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2022-49068

Affected products (as reported)

VendorProductVersions
Linux Linux 5afd80c393f4e87451f14eefb7f2f24daf434e06 – before 07cacfd9d9dc134557ac8866c73d570a59b3d1f3f0bfa76a11e93d0fe2c896fcb566568c5e8b5d3f – before a04d37ddfe4be431b9e52e8504490376ab0a39a4f0bfa76a11e93d0fe2c896fcb566568c5e8b5d3f – before 6d82ad13c4110e73c7b0392f00534a1502a1b52096f1be29492d9e2fb97bb27f824478ab8cd3ab865.15.27 – before 5.15.355.16.13 – before 5.17
Linux Linux 5.17

References