CVE-2023-52462 Information

Description

In the Linux kernel the following vulnerability has been resolved:

bpf: fix check for attempt to corrupt spilled pointer

When register is spilled onto a stack as a 1/2/4-byte register we set slot_type[BPF_REG_SIZE - 1] (plus potentially few more below it depending on actual spill size). So to check if some stack slot has spilled register we need to consult slot_type[7] not slot_type[0].

To avoid the need to remember and double-check this in the future just use is_spilled_reg() helper.

Reference

https://git.kernel.org/stable/c/2757f17972d87773b3677777f5682510f13c66ef https://git.kernel.org/stable/c/67e6707f07354ed1acb4e65552e97c60cf9d69cf https://git.kernel.org/stable/c/fc3e3c50a0a4cac1463967c110686189e4a59104 https://git.kernel.org/stable/c/8dc15b0670594543c356567a1a45b0182ec63174 https://git.kernel.org/stable/c/40617d45ea05535105e202a8a819e388a2b1f036 https://git.kernel.org/stable/c/ab125ed3ec1c10ccc36bc98c7a4256ad114a3dae