Buffer overflow in Linux kernel - CVE-2021-47040
Published: June 8, 2024 / Updated: May 13, 2025
Vulnerability identifier: #VU91439
CSH Severity: Low
CVSS v4: 8.5 [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]
CVE-ID: CVE-2021-47040
CWE-ID: CWE-119
Exploitation vector: Local access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to memory corruption within the io_remove_buffers() and io_provide_buffers_prep() functions in fs/io_uring.c. A local user can escalate privileges on the system.
Affected software
Linux kernel
openEuler
kernel-source
kernel
kernel-tools
perf-debuginfo
python2-perf
kernel-devel
python3-perf
python2-perf-debuginfo
bpftool-debuginfo
kernel-tools-debuginfo
kernel-debuginfo
kernel-tools-devel
kernel-debugsource
python3-perf-debuginfo
bpftool
perf
openEuler
kernel-source
kernel
kernel-tools
perf-debuginfo
python2-perf
kernel-devel
python3-perf
python2-perf-debuginfo
bpftool-debuginfo
kernel-tools-debuginfo
kernel-debuginfo
kernel-tools-devel
kernel-debugsource
python3-perf-debuginfo
bpftool
perf
How to mitigate CVE-2021-47040
Install update from vendor's website.
Linux kernel - addressed in versions 5.10.37, 5.11.21, 5.12.4, 5.13
kernel-source - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-tools - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
perf-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
python2-perf - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-devel - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
python3-perf - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
python2-perf-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
bpftool-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-tools-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-tools-devel - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-debugsource - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
python3-perf-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
bpftool - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
perf - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-source - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-tools - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
perf-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
python2-perf - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-devel - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
python3-perf - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
python2-perf-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
bpftool-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-tools-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-tools-devel - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
kernel-debugsource - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
python3-perf-debuginfo - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
bpftool - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
perf - addressed in versions 4.19.90-2403.3.0.0244, 4.19.90-2403.4.0.0271
External References
- https://git.kernel.org/stable/c/cbbc13b115b8f18e0a714d89f87fbdc499acfe2d
- https://git.kernel.org/stable/c/51bf90901952aaac564bbdb36b2b503050c53dd9
- https://git.kernel.org/stable/c/84b8c266c4bfe9ed5128e13253c388deb74b1b03
- https://git.kernel.org/stable/c/38134ada0ceea3e848fe993263c0ff6207fd46e7
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.10.37
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.21
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.4
- https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13