From 506ada89629ec7059b96ecfb0dc7d33ece0103ca Mon Sep 17 00:00:00 2001 From: Eduard Zingerman Date: Fri, 4 Sep 2026 17:05:56 -0700 Subject: bpf: mark a NULL kfunc argument precise check_kfunc_arg() allows bpf_register_is_null() for nullable arguments w/o marking the underlying scalar register precise. Hence a checkpoint created on such a path would prune against arbitrary scalar value. Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)") Signed-off-by: Eduard Zingerman Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com Signed-off-by: Alexei Starovoitov --- drivers/misc/lkdtm/rodata.c | 11 +++++++++++ 1 file changed, 11 insertions(+) create mode 100644 drivers/misc/lkdtm/rodata.c (limited to 'drivers/misc/lkdtm/rodata.c') diff --git a/drivers/misc/lkdtm/rodata.c b/drivers/misc/lkdtm/rodata.c new file mode 100644 index 000000000..baacb876d --- /dev/null +++ b/drivers/misc/lkdtm/rodata.c @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * This includes functions that are meant to live entirely in .rodata + * (via objcopy tricks), to validate the non-executability of .rodata. + */ +#include "lkdtm.h" + +void noinstr lkdtm_rodata_do_nothing(void) +{ + /* Does nothing. We just want an architecture agnostic "return". */ +} -- cgit v1.3.1