{"cve":"CVE-2021-47335","nvd":{"published":"2024-05-21T15:15:20.350","modified":"2026-08-11T03:17:20.253","status":"Analyzed","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances\n\nAs syzbot reported, there is an use-after-free issue during f2fs recovery:\n\nUse-after-free write at 0xffff88823bc16040 (in kfence-#10):\n kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486\n f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869\n f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945\n mount_bdev+0x26c/0x3a0 fs/super.c:1367\n legacy_get_tree+0xea/0x180 fs/fs_context.c:592\n vfs_get_tree+0x86/0x270 fs/super.c:1497\n do_new_mount fs/namespace.c:2905 [inline]\n path_mount+0x196f/0x2be0 fs/namespace.c:3235\n do_mount fs/namespace.c:3248 [inline]\n __do_sys_mount fs/namespace.c:3456 [inline]\n __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433\n do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nThe root cause is multi f2fs filesystem instances can race on accessing\nglobal fsync_entry_slab pointer, result in use-after-free issue of slab\ncache, fixes to init/destroy this slab cache only once during module\ninit/destroy procedure to avoid this issue.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-416"],"references":["https://git.kernel.org/stable/c/79fa5d944c875711253a23b8155b36883c696409","https://git.kernel.org/stable/c/86786603014e0a22d0d6af8e80ae4b8687927048","https://git.kernel.org/stable/c/cad83c968c2ebe97905f900326988ed37146c347","https://git.kernel.org/stable/c/e472b276a0d2180808009be38105e12754432e2a","https://git.kernel.org/stable/c/79fa5d944c875711253a23b8155b36883c696409"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T21:50:30.954589733+00:00"},"epss":{"cve":"CVE-2021-47335","score":0.00232,"percentile":0.14138,"date":"2026-11-01"},"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."]}