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Vulnerability · Published Jun 18, 2025 · Assigned by Linux

CVE-2022-50021ext4: block range must be validated before use in ext4_mb_clear_bb()

High 7.8

In plain English

A high-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 0.2% (higher than 10% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)7.8High
Exploit odds (30 days)0.2%top 89.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: ext4: block range must be validated before use in ext4_mb_clear_bb() Block range to free is validated in ext4_free_blocks() using ext4_inode_block_valid() and then it's passed to ext4_mb_clear_bb(). However in some situations on bigalloc file system the range might be adjusted after the validation in ext4_free_blocks() which can lead to troubles on corrupted file systems such as one found by syzkaller that resulted in the following BUG kernel BUG at fs/ext4/ext4.h:3319! PREEMPT SMP NOPTI CPU: 28 PID: 4243 Comm: repro Kdump: loaded Not tainted 5.19.0-rc6+ #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014 RIP: 0010:ext4_free_blocks+0x95e/0xa90 Call Trace: <TASK> ? lock_timer_base+0x61/0x80 ? __es_remove_extent+0x5a/0x760 ? __mod_timer+0x256/0x380 ? ext4_ind_truncate_ensure_credits+0x90/0x220 ext4_clear_blocks+0x107/0x1b0 ext4_free_data+0x15b/0x170 ext4_ind_truncate+0x214/0x2c0 ? _raw_spin_unlock+0x15/0x30 ? ext4_discard_preallocations+0x15a/0x410 ? ext4_journal_check_start+0xe/0x90 ? __ext4_journal_start_sb+0x2f/0x110 ext4_truncate+0x1b5/0x460 ? __ext4_journal_start_sb+0x2f/0x110 ext4_evict_inode+0x2b4/0x6f0 evict+0xd0/0x1d0 ext4_enable_quotas+0x11f/0x1f0 ext4_orphan_cleanup+0x3de/0x430 ? proc_create_seq_private+0x43/0x50 ext4_fill_super+0x295f/0x3ae0 ? snprintf+0x39/0x40 ? sget_fc+0x19c/0x330 ? ext4_reconfigure+0x850/0x850 get_tree_bdev+0x16d/0x260 vfs_get_tree+0x25/0xb0 path_mount+0x431/0xa70 __x64_sys_mount+0xe2/0x120 do_syscall_64+0x5b/0x80 ? do_user_addr_fault+0x1e2/0x670 ? exc_page_fault+0x70/0x170 entry_SYSCALL_64_after_hwframe+0x46/0xb0 RIP: 0033:0x7fdf4e512ace Fix it by making sure that the block range is properly validated before used every time it changes in ext4_free_blocks() or ext4_mb_clear_bb().

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.0.2-1DEBIAN-CVE-2022-50021
Debian:13linux6.0.2-1DEBIAN-CVE-2022-50021
Debian:14linux6.0.2-1DEBIAN-CVE-2022-50021
Ubuntu:22.04:LTSlinux5.15.0-79.86UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-aws5.15.0-1042.47UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-azure5.15.0-1045.52UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1045.52.1UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-gcp5.15.0-1039.47UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-gke5.15.0-1039.44UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1025.30UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-ibm5.15.0-1035.38UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1037.42UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-kvm5.15.0-1039.44UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-79.88UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1030.30UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1016.16UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1002.2UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-oracle5.15.0-1040.46UBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-raspi5.15.0-1035.38UBUNTU-CVE-2022-50021
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2022-50021
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2022-50021
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2022-50021
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1025.29UBUNTU-CVE-2022-50021

Affected products (as reported)

VendorProductVersions
Linux Linux 84130193e0e6568dfdfb823f0e1e19aec80aff6e – before 7550aade978371ac582f6d43b14c4cb89ca5446384130193e0e6568dfdfb823f0e1e19aec80aff6e – before 560a2744cbbf03cac65a6394f9b0d99aa437c86784130193e0e6568dfdfb823f0e1e19aec80aff6e – before a2522041d248a8c969cbbc97e1fc2cd8b4de120d84130193e0e6568dfdfb823f0e1e19aec80aff6e – before 1e1c2b86ef86a8477fd9b9a4f48a6bfe235606f6
Linux Linux 3.2

References