diff options
| author |   Xu Yunxiang <xyx2021@mail.ustc.edu.cn> | 2026-09-21 05:04:22 +0800 |
|---|---|---|
| committer |   Andrii Nakryiko <andrii@kernel.org> | 2026-09-21 15:00:59 -0700 |
| commit | 8244668cbbffc8e242b2c5204a2dea20bfca096c (patch) | |
| tree | 8ee174c370ab79043a293db4a325e7d7416c15c4 | |
| parent | bpf: Reject non-negative offsets in stack_slot_obj_get_spi() (diff) | |
selftests/bpf: Reject iterator destruction through fp+0
Add a verifier regression test that initializes a numeric iterator at fp-8
and attempts to destroy it through fp+0. The verifier must reject the
non-negative offset instead of treating it as the initialized stack slot.
Check the offset diagnostic to ensure rejection happens at the stack
object address check. The numeric iterator destroy operation is a no-op;
this test checks verifier rejection and does not run the program.
Signed-off-by: Xu Yunxiang <xyx2021@mail.ustc.edu.cn>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Sun Jian <sun.jian.kdev@gmail.com>
Link: https://lore.kernel.org/bpf/20260920210423.345636-3-xyx2021@mail.ustc.edu.cn
| -rw-r--r-- | tools/testing/selftests/bpf/progs/iters_state_safety.c | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/tools/testing/selftests/bpf/progs/iters_state_safety.c b/tools/testing/selftests/bpf/progs/iters_state_safety.c index 646026430e9b..e5bb9fe6d5e5 100644 --- a/tools/testing/selftests/bpf/progs/iters_state_safety.c +++ b/tools/testing/selftests/bpf/progs/iters_state_safety.c @@ -52,6 +52,28 @@ int create_and_destroy(void *ctx) return 0; } +/* fp+0 is not a stack slot. bpf_get_spi(0) used to alias spi 0 (fp-8). */ +SEC("?raw_tp") +__failure __msg("cannot pass in iter at an offset=0") +int destroy_fp0_fail(void *ctx) +{ + struct bpf_iter_num iter; + + asm volatile ("r1 = %[iter];" + "r2 = 0;" + "r3 = 1000;" + "call %[bpf_iter_num_new];" + /* r10 is fp+0, one byte above the top of the BPF stack */ + "r1 = r10;" + "call %[bpf_iter_num_destroy];" + : + : __imm_ptr(iter), ITER_HELPERS + : __clobber_common + ); + + return 0; +} + SEC("?raw_tp") __failure __msg("Unreleased reference id=1") int create_and_forget_to_destroy_fail(void *ctx) |