CVE-2021-46974: bpf: Fix masking negation logic upon negative dst register

First published: Tue Feb 27 2024(Updated: )

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.

Credit: 416baaa9-dc9f-4396-8d5f-8c081fb06d67

Never miss a vulnerability like this again

Sign up to SecAlerts for real-time vulnerability data matched to your software, aggregated from hundreds of sources.

Read MoreStart Free Trial

• agent/title
• agent/references
• agent/type
• agent/description
• agent/first-publish-date
• agent/author
• agent/event
• collector/mitre-cve
• source/MITRE
• collector/nvd-api
• source/NVD
• agent/software-canonical-lookup
• agent/last-modified-date
• agent/severity
• agent/remedy
• agent/softwarecombine
• agent/tags
• vendor/linux
• canonical/linux linux kernel
• version/linux linux kernel/4.14.113
• version/linux linux kernel/4.19.19
• version/linux linux kernel/5.0
• version/linux linux kernel/5.5
• version/linux linux kernel/5.11
• version/linux linux kernel/5.12