4b708b7b1a
The VPD implementation from Chromium Vital Product Data project used to
parse data from untrusted input without checking if the meta data is
invalid or corrupted. For example, the size from decoded content may
be negative value, or larger than whole input buffer. Such invalid data
may cause buffer overflow.
To fix that, the size parameters passed to vpd_decode functions should
be changed to unsigned integer (u32) type, and the parsing of entry
header should be refactored so every size field is correctly verified
before starting to decode.
Fixes: ad2ac9d5c5 ("firmware: Google VPD: import lib_vpd source files")
Signed-off-by: Hung-Te Lin <hungte@chromium.org>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/20190830022402.214442-1-hungte@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
51 lines
1.2 KiB
C
51 lines
1.2 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* vpd_decode.h
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*
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* Google VPD decoding routines.
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*
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* Copyright 2017 Google Inc.
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*/
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#ifndef __VPD_DECODE_H
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#define __VPD_DECODE_H
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#include <linux/types.h>
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enum {
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VPD_OK = 0,
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VPD_FAIL,
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};
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enum {
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VPD_TYPE_TERMINATOR = 0,
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VPD_TYPE_STRING,
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VPD_TYPE_INFO = 0xfe,
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VPD_TYPE_IMPLICIT_TERMINATOR = 0xff,
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};
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/* Callback for vpd_decode_string to invoke. */
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typedef int vpd_decode_callback(const u8 *key, u32 key_len,
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const u8 *value, u32 value_len,
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void *arg);
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/*
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* vpd_decode_string
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*
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* Given the encoded string, this function invokes callback with extracted
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* (key, value). The *consumed will be plused the number of bytes consumed in
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* this function.
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*
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* The input_buf points to the first byte of the input buffer.
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*
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* The *consumed starts from 0, which is actually the next byte to be decoded.
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* It can be non-zero to be used in multiple calls.
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*
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* If one entry is successfully decoded, sends it to callback and returns the
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* result.
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*/
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int vpd_decode_string(const u32 max_len, const u8 *input_buf, u32 *consumed,
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vpd_decode_callback callback, void *callback_arg);
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#endif /* __VPD_DECODE_H */
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