What’s Vulnerable › Vulnerabilities
CVE-2021-45402
- Severity: medium (CVSS 5.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.4% probability of exploitation in the next 30 days
- Public exploit or detection template: yes
- Published: 2022-02-11 · updated 2026-10-08
- Weakness: CWE-668
Description
The check_alu_op() function in kernel/bpf/verifier.c in the Linux kernel through v5.16-rc5 did not properly update bounds while handling the mov32 instruction, which allows local users to obtain potentially sensitive address information, aka a "pointer leak."
Affected products
- Linux kernel: before 5.16; 5.16-rc1, 5.16-rc2, 5.16-rc3, 5.16-rc4, 5.16-rc5 — fixed in 5.16
How to fix
Upgrade to a fixed version: Linux kernel 5.16. Check the vendor advisory for mitigations.
References
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=3cf2b61eb06765e27fec6799292d9fb46d0b7e60
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=b1a7288dedc6caf9023f2676b4f5ed34cf0d4029
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=e572ff80f05c33cd0cb4860f864f5c9c044280b6
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=3cf2b61eb06765e27fec6799292d9fb46d0b7e60
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=b1a7288dedc6caf9023f2676b4f5ed34cf0d4029
- https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=e572ff80f05c33cd0cb4860f864f5c9c044280b6
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