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| author | Eduard Zingerman <eddyz87@gmail.com> | 2026-09-04 17:05:56 -0700 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-09-04 18:17:30 -0700 |
| commit | 506ada89629ec7059b96ecfb0dc7d33ece0103ca (patch) | |
| tree | 0b07297409b68d2333fb4f0eae7f3b072eb68d4c /arch/arm/lib/memchr.S | |
| download | linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.tar.gz linux-stable-506ada89629ec7059b96ecfb0dc7d33ece0103ca.zip | |
bpf: mark a NULL kfunc argument precisegrafted
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 <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'arch/arm/lib/memchr.S')
| -rw-r--r-- | arch/arm/lib/memchr.S | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/arch/arm/lib/memchr.S b/arch/arm/lib/memchr.S new file mode 100644 index 000000000..95bedafd0 --- /dev/null +++ b/arch/arm/lib/memchr.S @@ -0,0 +1,23 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* + * linux/arch/arm/lib/memchr.S + * + * Copyright (C) 1995-2000 Russell King + * + * ASM optimised string functions + */ +#include <linux/linkage.h> +#include <asm/assembler.h> + + .text + .align 5 +ENTRY(memchr) +1: subs r2, r2, #1 + bmi 2f + ldrb r3, [r0], #1 + teq r3, r1 + bne 1b + sub r0, r0, #1 +2: movne r0, #0 + ret lr +ENDPROC(memchr) |