cbcvebase.
CVE-2022-50021
published 2025-06-18

CVE-2022-50021: 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…

PriorityP339high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.17%
6.4th percentile
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: ? 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

13 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.0.2-1 (bookworm)linux 6.0.2-1 (bookworm)
linuxlinux——
linuxlinux>= 84130193e0e6568dfdfb823f0e1e19aec80aff6e < 7550aade978371ac582f6d43b14c4cb89ca544637550aade978371ac582f6d43b14c4cb89ca54463
linuxlinux>= 84130193e0e6568dfdfb823f0e1e19aec80aff6e < 560a2744cbbf03cac65a6394f9b0d99aa437c867560a2744cbbf03cac65a6394f9b0d99aa437c867
linuxlinux>= 84130193e0e6568dfdfb823f0e1e19aec80aff6e < a2522041d248a8c969cbbc97e1fc2cd8b4de120da2522041d248a8c969cbbc97e1fc2cd8b4de120d
linuxlinux>= 84130193e0e6568dfdfb823f0e1e19aec80aff6e < 1e1c2b86ef86a8477fd9b9a4f48a6bfe235606f61e1c2b86ef86a8477fd9b9a4f48a6bfe235606f6
linuxlinux_kernel< 5.10.1755.10.175
linuxlinux_kernel>= 0 < 5.10.178-15.10.178-1
linuxlinux_kernel>= 0 < 6.0.2-16.0.2-1
linuxlinux_kernel>= 0 < 6.0.2-16.0.2-1
linuxlinux_kernel>= 0 < 6.0.2-16.0.2-1
linuxlinux_kernel>= 5.11 < 5.15.1035.15.103
linuxlinux_kernel>= 5.16 < 5.19.45.19.4

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8HIGH
vendor_redhat7.8HIGH
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