vulnerability
Debian: CVE-2021-3491: linux -- security update
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 7 | (AV:L/AC:L/Au:N/C:C/I:C/A:C) | Jun 4, 2021 | Jul 30, 2024 | Aug 15, 2025 |
Severity
7
CVSS
(AV:L/AC:L/Au:N/C:C/I:C/A:C)
Published
Jun 4, 2021
Added
Jul 30, 2024
Modified
Aug 15, 2025
Description
The io_uring subsystem in the Linux kernel allowed the MAX_RW_COUNT limit to be bypassed in the PROVIDE_BUFFERS operation, which led to negative values being usedin mem_rw when reading /proc/<PID>/mem. This could be used to create a heap overflow leading to arbitrary code execution in the kernel. It was addressed via commit d1f82808877b ("io_uring: truncate lengths larger than MAX_RW_COUNT on provide buffers") (v5.13-rc1) and backported to the stable kernels in v5.12.4, v5.11.21, and v5.10.37. It was introduced in ddf0322db79c ("io_uring: add IORING_OP_PROVIDE_BUFFERS") (v5.7-rc1).
Solution
debian-upgrade-linux
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