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@xxxxxxxxx> --- Changes in v2: - Add fix and cc tags. - Link to v1: https://lore.kernel.org/r/20231026-fix-check-stack-write-v1-0-6b325ef3ce7e@xxxxxxxxx --- 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: f1c73396133cb3d913e2075298005644ee8dfade change-id: 20231026-fix-check-stack-write-c40996694dfa Best regards, -- Hao Sun <sunhao.th@xxxxxxxxx>