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 --- arch/arm/lib/strchr.S | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) create mode 100644 arch/arm/lib/strchr.S (limited to 'arch/arm/lib/strchr.S') diff --git a/arch/arm/lib/strchr.S b/arch/arm/lib/strchr.S new file mode 100644 index 000000000..09e2cc8a8 --- /dev/null +++ b/arch/arm/lib/strchr.S @@ -0,0 +1,24 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/strchr.S + * + * Copyright (C) 1995-2000 Russell King + * + * ASM optimised string functions + */ +#include +#include + + .text + .align 5 +ENTRY(strchr) + and r1, r1, #0xff +1: ldrb r2, [r0], #1 + teq r2, r1 + teqne r2, #0 + bne 1b + teq r2, r1 + movne r0, #0 + subeq r0, r0, #1 + ret lr +ENDPROC(strchr) -- cgit v1.3.1