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authorHung-Te Lin <hungte@chromium.org>2019-06-12 16:59:24 +0800
committerPatrick Georgi <pgeorgi@google.com>2019-06-21 08:41:16 +0000
commitf6317b4892d8d295312ffd7a8b4caccf2610c25e (patch)
treee58d4a28d3d777beaaa8d8b20ba6eacebc381013
parentaa5e8e099e83647cd6347bcbc82e2c11a6cac1d7 (diff)
downloadcoreboot-f6317b4892d8d295312ffd7a8b4caccf2610c25e.tar.xz
src/driver/vpd: Update vpd_decode from upstream
The upstream vpd_decode.c has been revised to prevent overrun of decoded contents. BUG=chromium:967209 TEST=select VPD config on kukui; make; boots on at least kukui boards. Change-Id: I1a50670a66b7b174d2a432c29d90152b86c32982 Signed-off-by: Hung-Te Lin <hungte@chromium.org> Reviewed-on: https://review.coreboot.org/c/coreboot/+/33414 Tested-by: build bot (Jenkins) <no-reply@coreboot.org> Reviewed-by: Julius Werner <jwerner@chromium.org>
-rw-r--r--src/drivers/vpd/vpd_decode.c51
-rw-r--r--src/drivers/vpd/vpd_decode.h21
2 files changed, 30 insertions, 42 deletions
diff --git a/src/drivers/vpd/vpd_decode.c b/src/drivers/vpd/vpd_decode.c
index 0eab704ca8..527c50818e 100644
--- a/src/drivers/vpd/vpd_decode.c
+++ b/src/drivers/vpd/vpd_decode.c
@@ -8,7 +8,7 @@
*/
#include "vpd_decode.h"
-int vpd_decode_len(
+static int vpd_decode_len(
const u32 max_len, const u8 *in, u32 *length, u32 *decoded_len)
{
u8 more;
@@ -32,15 +32,36 @@ int vpd_decode_len(
return VPD_DECODE_OK;
}
+static int vpd_decode_entry(
+ const u32 max_len, const u8 *input_buf, u32 *consumed,
+ const u8 **entry, u32 *entry_len)
+{
+ u32 decoded_len;
+
+ if (vpd_decode_len(max_len - *consumed, &input_buf[*consumed],
+ entry_len, &decoded_len) != VPD_DECODE_OK)
+ return VPD_DECODE_FAIL;
+ if (max_len - *consumed < decoded_len)
+ return VPD_DECODE_FAIL;
+
+ *consumed += decoded_len;
+ *entry = input_buf + *consumed;
+
+ /* entry_len is untrusted data and must be checked again. */
+ if (max_len - *consumed < *entry_len)
+ return VPD_DECODE_FAIL;
+
+ *consumed += *entry_len;
+ return VPD_DECODE_OK;
+}
+
int vpd_decode_string(
const u32 max_len, const u8 *input_buf, u32 *consumed,
vpd_decode_callback callback, void *callback_arg)
{
int type;
- int res;
u32 key_len;
u32 value_len;
- u32 decoded_len;
const u8 *key;
const u8 *value;
@@ -55,30 +76,14 @@ int vpd_decode_string(
case VPD_TYPE_STRING:
(*consumed)++;
- /* key */
- res = vpd_decode_len(max_len - *consumed, &input_buf[*consumed],
- &key_len, &decoded_len);
- /* key name cannot be empty, and must be followed by value. */
- if (res != VPD_DECODE_OK || key_len < 1 ||
- *consumed + decoded_len + key_len >= max_len)
+ if (vpd_decode_entry(max_len, input_buf, consumed, &key,
+ &key_len) != VPD_DECODE_OK)
return VPD_DECODE_FAIL;
- *consumed += decoded_len;
- key = &input_buf[*consumed];
- *consumed += key_len;
-
- /* value */
- res = vpd_decode_len(max_len - *consumed, &input_buf[*consumed],
- &value_len, &decoded_len);
- /* value can be empty (value_len = 0). */
- if (res != VPD_DECODE_OK ||
- *consumed + decoded_len + value_len > max_len)
+ if (vpd_decode_entry(max_len, input_buf, consumed, &value,
+ &value_len) != VPD_DECODE_OK)
return VPD_DECODE_FAIL;
- *consumed += decoded_len;
- value = &input_buf[*consumed];
- *consumed += value_len;
-
if (type == VPD_TYPE_STRING)
return callback(key, key_len, value, value_len,
callback_arg);
diff --git a/src/drivers/vpd/vpd_decode.h b/src/drivers/vpd/vpd_decode.h
index 99ca7efa81..5d595f367f 100644
--- a/src/drivers/vpd/vpd_decode.h
+++ b/src/drivers/vpd/vpd_decode.h
@@ -30,28 +30,11 @@ typedef int vpd_decode_callback(
void *arg);
/*
- * vpd_decode_len
- *
- * Given an encoded string, this function extracts the length of content
- * (either key or value). The *consumed will contain the number of bytes
- * consumed.
- *
- * The input_buf points to the first byte of the input buffer.
- *
- * The *consumed starts from 0, which is actually the next byte to be decoded.
- * It can be non-zero to be used in multiple calls.
- *
- * Returns VPD_DECODE_OK on success, otherwise VPD_DECODE_FAIL.
- */
-int vpd_decode_len(
- const u32 max_len, const u8 *in, u32 *length, u32 *decoded_len);
-
-/*
* vpd_decode_string
*
* Given the encoded string, this function invokes callback with extracted
- * (key, value). The *consumed will be plused the number of bytes consumed in
- * this function.
+ * (key, value). The *consumed will be incremented by the number of bytes
+ * consumed in this function.
*
* The input_buf points to the first byte of the input buffer.
*