CVE-2021-46974
What it is
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix masking negation logic upon negative dst register The negation logic for the case where the off_reg is sitting in the dst register is not correct given then we cannot just invert the add to a sub or vice versa. As a fix, perform the final bitwise and-op unconditionally into AX from the off_reg, then move the pointer from the src to dst and finally use AX as the source for the original pointer arithmetic operation such that the inversion yields a correct result. The single non-AX mov in between is possible given constant blinding is retaining it as it's not an immediate based operation.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 7.1 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Modified
Affected
- Linux Kernel < 4.14.233
- Linux Kernel < 4.19.190
- Linux Kernel < 5.4.117
- Linux Kernel < 5.10.35
- Linux Kernel < 5.11.19
- Linux Kernel < 5.12.2
Attack profile CVSS 3.1 · 7.1
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-46974.md and follow it. Check whether this project is affected by CVE-2021-46974. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/0e2dfdc74a7f4036127356d42ea59388f153f42c
- https://git.kernel.org/stable/c/2cfa537674cd1051a3b8111536d77d0558f33d5d
- https://git.kernel.org/stable/c/4d542ddb88fb2f39bf7f14caa2902f3e8d06f6ba
- https://git.kernel.org/stable/c/53e0db429b37a32b8fc706d0d90eb4583ad13848
- https://git.kernel.org/stable/c/6eba92a4d4be8feb4dc33976abac544fa99d6ecc
- https://git.kernel.org/stable/c/7cf64d8679ca1cb20cf57d6a88bfee79a0922a66
- https://git.kernel.org/stable/c/b9b34ddbe2076ade359cd5ce7537d5ed019e9807
- https://git.kernel.org/stable/c/0e2dfdc74a7f4036127356d42ea59388f153f42c
- https://git.kernel.org/stable/c/2cfa537674cd1051a3b8111536d77d0558f33d5d
- https://git.kernel.org/stable/c/4d542ddb88fb2f39bf7f14caa2902f3e8d06f6ba
References
- https://git.kernel.org/stable/c/0e2dfdc74a7f4036127356d42ea59388f153f42c
- https://git.kernel.org/stable/c/2cfa537674cd1051a3b8111536d77d0558f33d5d
- https://git.kernel.org/stable/c/4d542ddb88fb2f39bf7f14caa2902f3e8d06f6ba
- https://git.kernel.org/stable/c/53e0db429b37a32b8fc706d0d90eb4583ad13848
- https://git.kernel.org/stable/c/6eba92a4d4be8feb4dc33976abac544fa99d6ecc
- https://git.kernel.org/stable/c/7cf64d8679ca1cb20cf57d6a88bfee79a0922a66
- https://git.kernel.org/stable/c/b9b34ddbe2076ade359cd5ce7537d5ed019e9807
- https://git.kernel.org/stable/c/0e2dfdc74a7f4036127356d42ea59388f153f42c
- https://git.kernel.org/stable/c/2cfa537674cd1051a3b8111536d77d0558f33d5d
- https://git.kernel.org/stable/c/4d542ddb88fb2f39bf7f14caa2902f3e8d06f6ba
- https://git.kernel.org/stable/c/53e0db429b37a32b8fc706d0d90eb4583ad13848
- https://git.kernel.org/stable/c/6eba92a4d4be8feb4dc33976abac544fa99d6ecc
- https://git.kernel.org/stable/c/7cf64d8679ca1cb20cf57d6a88bfee79a0922a66
- https://git.kernel.org/stable/c/b9b34ddbe2076ade359cd5ce7537d5ed019e9807