Use-after-free in Linux kernel - CVE-2021-47335
Published: May 31, 2024 / Updated: May 14, 2025
Vulnerability identifier: #VU90129
CSH Severity: Low
CVSS v4.0: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear
CVE-ID: CVE-2021-47335
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vendor: Linux Foundation
Affected software:
Linux kernel
Linux kernel
Detailed vulnerability description
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error within the init_f2fs_fs() and exit_f2fs_fs() functions in fs/f2fs/super.c, within the f2fs_recover_fsync_data() function in fs/f2fs/recovery.c, within the f2fs_destroy_garbage_collection_cache() function in fs/f2fs/f2fs.h. A local user can escalate privileges on the system.
How to mitigate CVE-2021-47335
Install update from vendor's website.
Sources
- https://git.kernel.org/stable/c/86786603014e0a22d0d6af8e80ae4b8687927048
- https://git.kernel.org/stable/c/79fa5d944c875711253a23b8155b36883c696409
- https://git.kernel.org/stable/c/e472b276a0d2180808009be38105e12754432e2a
- https://git.kernel.org/stable/c/cad83c968c2ebe97905f900326988ed37146c347
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.51
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.18
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13.3
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.14