{"cve":"CVE-2022-50021","nvd":{"published":"2025-06-18T11:15:30.280","modified":"2026-06-17T05:22:34.583","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: block range must be validated before use in ext4_mb_clear_bb()\n\nBlock range to free is validated in ext4_free_blocks() using\next4_inode_block_valid() and then it's passed to ext4_mb_clear_bb().\nHowever in some situations on bigalloc file system the range might be\nadjusted after the validation in ext4_free_blocks() which can lead to\ntroubles on corrupted file systems such as one found by syzkaller that\nresulted in the following BUG\n\nkernel BUG at fs/ext4/ext4.h:3319!\nPREEMPT SMP NOPTI\nCPU: 28 PID: 4243 Comm: repro Kdump: loaded Not tainted 5.19.0-rc6+ #1\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014\nRIP: 0010:ext4_free_blocks+0x95e/0xa90\nCall Trace:\n <TASK>\n ? lock_timer_base+0x61/0x80\n ? __es_remove_extent+0x5a/0x760\n ? __mod_timer+0x256/0x380\n ? ext4_ind_truncate_ensure_credits+0x90/0x220\n ext4_clear_blocks+0x107/0x1b0\n ext4_free_data+0x15b/0x170\n ext4_ind_truncate+0x214/0x2c0\n ? _raw_spin_unlock+0x15/0x30\n ? ext4_discard_preallocations+0x15a/0x410\n ? ext4_journal_check_start+0xe/0x90\n ? __ext4_journal_start_sb+0x2f/0x110\n ext4_truncate+0x1b5/0x460\n ? __ext4_journal_start_sb+0x2f/0x110\n ext4_evict_inode+0x2b4/0x6f0\n evict+0xd0/0x1d0\n ext4_enable_quotas+0x11f/0x1f0\n ext4_orphan_cleanup+0x3de/0x430\n ? proc_create_seq_private+0x43/0x50\n ext4_fill_super+0x295f/0x3ae0\n ? snprintf+0x39/0x40\n ? sget_fc+0x19c/0x330\n ? ext4_reconfigure+0x850/0x850\n get_tree_bdev+0x16d/0x260\n vfs_get_tree+0x25/0xb0\n path_mount+0x431/0xa70\n __x64_sys_mount+0xe2/0x120\n do_syscall_64+0x5b/0x80\n ? do_user_addr_fault+0x1e2/0x670\n ? exc_page_fault+0x70/0x170\n entry_SYSCALL_64_after_hwframe+0x46/0xb0\nRIP: 0033:0x7fdf4e512ace\n\nFix it by making sure that the block range is properly validated before\nused every time it changes in ext4_free_blocks() or ext4_mb_clear_bb().","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/1e1c2b86ef86a8477fd9b9a4f48a6bfe235606f6","https://git.kernel.org/stable/c/560a2744cbbf03cac65a6394f9b0d99aa437c867","https://git.kernel.org/stable/c/7550aade978371ac582f6d43b14c4cb89ca54463","https://git.kernel.org/stable/c/a2522041d248a8c969cbbc97e1fc2cd8b4de120d"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:03:23.287444849+00:00"},"epss":{"cve":"CVE-2022-50021","score":0.00204,"percentile":0.10362,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}