forked from mirrors/linux
75cf029027
To avoid false positives, KMSAN needs to unpoison the data copied from the userspace. To detect infoleaks - check the memory buffer passed to copy_to_user(). Link: https://lkml.kernel.org/r/20220915150417.722975-19-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Reviewed-by: Marco Elver <elver@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Andrey Konovalov <andreyknvl@google.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Borislav Petkov <bp@alien8.de> Cc: Christoph Hellwig <hch@lst.de> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Eric Biggers <ebiggers@google.com> Cc: Eric Biggers <ebiggers@kernel.org> Cc: Eric Dumazet <edumazet@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Ilya Leoshkevich <iii@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kees Cook <keescook@chromium.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael S. Tsirkin <mst@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Petr Mladek <pmladek@suse.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
83 lines
2.4 KiB
C
83 lines
2.4 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
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/*
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* KMSAN checks to be used for one-off annotations in subsystems.
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*
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* Copyright (C) 2017-2022 Google LLC
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* Author: Alexander Potapenko <glider@google.com>
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*
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*/
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#ifndef _LINUX_KMSAN_CHECKS_H
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#define _LINUX_KMSAN_CHECKS_H
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#include <linux/types.h>
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#ifdef CONFIG_KMSAN
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/**
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* kmsan_poison_memory() - Mark the memory range as uninitialized.
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* @address: address to start with.
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* @size: size of buffer to poison.
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* @flags: GFP flags for allocations done by this function.
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*
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* Until other data is written to this range, KMSAN will treat it as
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* uninitialized. Error reports for this memory will reference the call site of
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* kmsan_poison_memory() as origin.
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*/
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void kmsan_poison_memory(const void *address, size_t size, gfp_t flags);
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/**
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* kmsan_unpoison_memory() - Mark the memory range as initialized.
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* @address: address to start with.
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* @size: size of buffer to unpoison.
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*
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* Until other data is written to this range, KMSAN will treat it as
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* initialized.
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*/
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void kmsan_unpoison_memory(const void *address, size_t size);
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/**
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* kmsan_check_memory() - Check the memory range for being initialized.
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* @address: address to start with.
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* @size: size of buffer to check.
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*
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* If any piece of the given range is marked as uninitialized, KMSAN will report
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* an error.
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*/
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void kmsan_check_memory(const void *address, size_t size);
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/**
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* kmsan_copy_to_user() - Notify KMSAN about a data transfer to userspace.
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* @to: destination address in the userspace.
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* @from: source address in the kernel.
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* @to_copy: number of bytes to copy.
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* @left: number of bytes not copied.
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*
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* If this is a real userspace data transfer, KMSAN checks the bytes that were
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* actually copied to ensure there was no information leak. If @to belongs to
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* the kernel space (which is possible for compat syscalls), KMSAN just copies
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* the metadata.
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*/
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void kmsan_copy_to_user(void __user *to, const void *from, size_t to_copy,
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size_t left);
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#else
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static inline void kmsan_poison_memory(const void *address, size_t size,
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gfp_t flags)
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{
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}
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static inline void kmsan_unpoison_memory(const void *address, size_t size)
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{
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}
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static inline void kmsan_check_memory(const void *address, size_t size)
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{
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}
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static inline void kmsan_copy_to_user(void __user *to, const void *from,
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size_t to_copy, size_t left)
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{
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}
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#endif
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#endif /* _LINUX_KMSAN_CHECKS_H */
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