b41013b518
[ Upstream commit 442f1e746e8187b9deb1590176f6b0ff19686b11 ]
Commit 4b708b7b1a2c ("firmware: google: check if size is valid when
decoding VPD data") adds length checks, but the new vpd_decode_entry()
function botched the logic -- it adds the key length twice, instead of
adding the key and value lengths separately.
On my local system, this means vpd.c's vpd_section_create_attribs() hits
an error case after the first attribute it parses, since it's no longer
looking at the correct offset. With this patch, I'm back to seeing all
the correct attributes in /sys/firmware/vpd/...
Fixes: 4b708b7b1a2c ("firmware: google: check if size is valid when decoding VPD data")
Cc: <stable@vger.kernel.org>
Cc: Hung-Te Lin <hungte@chromium.org>
Signed-off-by: Brian Norris <briannorris@chromium.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Link: https://lore.kernel.org/r/20190930214522.240680-1-briannorris@chromium.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
109 lines
2.3 KiB
C
109 lines
2.3 KiB
C
/*
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* vpd_decode.c
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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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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License v2.0 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#include <linux/export.h>
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#include "vpd_decode.h"
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static int vpd_decode_len(const u32 max_len, const u8 *in,
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u32 *length, u32 *decoded_len)
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{
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u8 more;
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int i = 0;
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if (!length || !decoded_len)
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return VPD_FAIL;
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*length = 0;
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do {
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if (i >= max_len)
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return VPD_FAIL;
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more = in[i] & 0x80;
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*length <<= 7;
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*length |= in[i] & 0x7f;
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++i;
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} while (more);
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*decoded_len = i;
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return VPD_OK;
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}
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static int vpd_decode_entry(const u32 max_len, const u8 *input_buf,
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u32 *_consumed, const u8 **entry, u32 *entry_len)
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{
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u32 decoded_len;
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u32 consumed = *_consumed;
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if (vpd_decode_len(max_len - consumed, &input_buf[consumed],
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entry_len, &decoded_len) != VPD_OK)
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return VPD_FAIL;
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if (max_len - consumed < decoded_len)
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return VPD_FAIL;
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consumed += decoded_len;
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*entry = input_buf + consumed;
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/* entry_len is untrusted data and must be checked again. */
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if (max_len - consumed < *entry_len)
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return VPD_FAIL;
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consumed += *entry_len;
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*_consumed = consumed;
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return VPD_OK;
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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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{
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int type;
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u32 key_len;
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u32 value_len;
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const u8 *key;
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const u8 *value;
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/* type */
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if (*consumed >= max_len)
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return VPD_FAIL;
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type = input_buf[*consumed];
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switch (type) {
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case VPD_TYPE_INFO:
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case VPD_TYPE_STRING:
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(*consumed)++;
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if (vpd_decode_entry(max_len, input_buf, consumed, &key,
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&key_len) != VPD_OK)
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return VPD_FAIL;
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if (vpd_decode_entry(max_len, input_buf, consumed, &value,
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&value_len) != VPD_OK)
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return VPD_FAIL;
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if (type == VPD_TYPE_STRING)
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return callback(key, key_len, value, value_len,
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callback_arg);
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break;
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default:
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return VPD_FAIL;
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}
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return VPD_OK;
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}
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