Re: [PATCH bpf-next 0/2] bpf: Fix incorrect immediate spill

Eduard Zingerman
2023-10-26T21:33:36Z

On Thu, 2023-10-26 at 17:13 +0200, Hao Sun wrote:
> Immediate is incorrectly cast to u32 before being spilled, losing sign
> information. The range information is incorrect after load again. Fix
> immediate spill by remove the cast. The second patch add a test case
> for this.
>
> Signed-off-by: Hao Sun <sunhao.th@gmail.com>

Thank you for finding and fixing this issue.

Acked-by: Eduard Zingerman <eddyz87@gmail.com>

> ---
> Hao Sun (2):
> bpf: Fix check_stack_write_fixed_off() to correctly spill imm
> selftests/bpf: Add test for immediate spilled to stack
>
> kernel/bpf/verifier.c | 2 +-
> tools/testing/selftests/bpf/verifier/bpf_st_mem.c | 32 +++++++++++++++++++++++
> 2 files changed, 33 insertions(+), 1 deletion(-)
> ---
> base-commit: 399f6185a1c02f39bcadb8749bc2d9d48685816f
> change-id: 20231026-fix-check-stack-write-c40996694dfa
>
> Best regards,