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 --- include/vdso/page.h | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+) create mode 100644 include/vdso/page.h (limited to 'include/vdso/page.h') diff --git a/include/vdso/page.h b/include/vdso/page.h new file mode 100644 index 000000000..bc47186c0 --- /dev/null +++ b/include/vdso/page.h @@ -0,0 +1,31 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef __VDSO_PAGE_H +#define __VDSO_PAGE_H + +#include + +/* + * PAGE_SHIFT determines the page size. + * + * Note: This definition is required because PAGE_SHIFT is used + * in several places throughout the codebase. + */ +#define PAGE_SHIFT CONFIG_PAGE_SHIFT + +#define PAGE_SIZE (_AC(1,UL) << CONFIG_PAGE_SHIFT) + +#if !defined(CONFIG_64BIT) +/* + * Applies only to 32-bit architectures. + * + * Subtle: (1 << CONFIG_PAGE_SHIFT) is an int, not an unsigned long. + * So if we assign PAGE_MASK to a larger type it gets extended the + * way we want (i.e. with 1s in the high bits) while masking a + * 64-bit value such as phys_addr_t. + */ +#define PAGE_MASK (~((1 << CONFIG_PAGE_SHIFT) - 1)) +#else +#define PAGE_MASK (~(PAGE_SIZE - 1)) +#endif + +#endif /* __VDSO_PAGE_H */ -- cgit v1.3.1