706d642b1d
ACKs with no ABI symbol lists like mainline,
don't let any unsigned modules load as every
access is being treated as violation as
NO_OF_UNPROTECTED_SYMBOLS will be 0 in this case.
Check NO_OF_UNPROTECTED_SYMBOLS and if it's 0,
allow every symbol access by unsigned modules;
so we can keep the feature enable and also not
break any devices. It should never be 0 with
kernel branches where KMI_SYMBOL_LISTS have been
enabled.
Bug: 257458145
Bug: 232430739
Test: TH
Fixes: e9669eeb2f45 ("ANDROID: GKI: Add module load time symbol protection")
Change-Id: Iab65e1425473e32baaad0d6c7f0d3eb007ae864f
Signed-off-by: Ramji Jiyani <ramjiyani@google.com>
(cherry picked from commit 8e00226a8fffa10b6383e448af785ce44451688e)
45 lines
1.1 KiB
C
45 lines
1.1 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright 2022 Google LLC
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* Author: ramjiyani@google.com (Ramji Jiyani)
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*/
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#include <linux/bsearch.h>
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#include <linux/errno.h>
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#include <linux/kernel.h>
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#include <linux/printk.h>
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#include <linux/string.h>
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/*
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* Build time generated header files
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*
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* gki_module_unprotected.h -- Symbols allowed to _access_ by unsigned modules
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*/
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#include "gki_module_unprotected.h"
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/* bsearch() comparision callback */
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static int cmp_name(const void *sym, const void *protected_sym)
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{
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return strncmp(sym, protected_sym, MAX_UNPROTECTED_NAME_LEN);
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}
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/**
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* gki_is_module_unprotected_symbol - Is a symbol unprotected for unsigned module?
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*
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* @name: Symbol being checked in list of unprotected symbols
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*/
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bool gki_is_module_unprotected_symbol(const char *name)
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{
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if (NO_OF_UNPROTECTED_SYMBOLS) {
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return bsearch(name, gki_unprotected_symbols, NO_OF_UNPROTECTED_SYMBOLS,
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MAX_UNPROTECTED_NAME_LEN, cmp_name) != NULL;
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} else {
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/*
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* If there are no symbols in unprotected list;
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* there isn't a KMI enforcement for the kernel.
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* Treat evertything accessible in this case.
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*/
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return true;
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}
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}
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