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/firmware/google/memconsole.c | 54 ++++++++++++++++++++++++++++++++++++ 1 file changed, 54 insertions(+) create mode 100644 drivers/firmware/google/memconsole.c (limited to 'drivers/firmware/google/memconsole.c') diff --git a/drivers/firmware/google/memconsole.c b/drivers/firmware/google/memconsole.c new file mode 100644 index 000000000..6138a1653 --- /dev/null +++ b/drivers/firmware/google/memconsole.c @@ -0,0 +1,54 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * memconsole.c + * + * Architecture-independent parts of the memory based BIOS console. + * + * Copyright 2017 Google Inc. + */ + +#include +#include +#include + +#include "memconsole.h" + +static ssize_t memconsole_read(struct file *filp, struct kobject *kobp, + const struct bin_attribute *bin_attr, char *buf, + loff_t pos, size_t count) +{ + ssize_t (*memconsole_read_func)(char *, loff_t, size_t); + + memconsole_read_func = bin_attr->private; + if (WARN_ON_ONCE(!memconsole_read_func)) + return -EIO; + + return memconsole_read_func(buf, pos, count); +} + +static struct bin_attribute memconsole_bin_attr = { + .attr = {.name = "log", .mode = 0444}, + .read = memconsole_read, +}; + +void memconsole_setup(ssize_t (*read_func)(char *, loff_t, size_t)) +{ + memconsole_bin_attr.private = read_func; +} +EXPORT_SYMBOL(memconsole_setup); + +int memconsole_sysfs_init(void) +{ + return sysfs_create_bin_file(firmware_kobj, &memconsole_bin_attr); +} +EXPORT_SYMBOL(memconsole_sysfs_init); + +void memconsole_exit(void) +{ + sysfs_remove_bin_file(firmware_kobj, &memconsole_bin_attr); +} +EXPORT_SYMBOL(memconsole_exit); + +MODULE_AUTHOR("Google, Inc."); +MODULE_DESCRIPTION("Architecture-independent parts of the memory based BIOS console"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1