# HG changeset patch
# User Uri Shkolnik <uris@xxxxxxxxxxxx>
# Date 1235483353 -7200
# Node ID ba9020b165e75b80e8c7b499e8068741982c44f6
# Parent 3caff6dae0753d2adb581b7ef5e309a1954820b2
Fixed use of freed memory in smsspicommon
From: Uri Shkolnik <uris@xxxxxxxxxxxx>
Moved the handling of "unused bytes" before the reporting of message found.
Priority: normal
Signed-off-by: Uri Shkolnik <uris@xxxxxxxxxxxx>
diff -r 3caff6dae075 -r ba9020b165e7 linux/drivers/media/dvb/siano/smsspicommon.c
--- a/linux/drivers/media/dvb/siano/smsspicommon.c Sun Feb 08 17:28:37 2009 +0200
+++ b/linux/drivers/media/dvb/siano/smsspicommon.c Tue Feb 24 15:49:13 2009 +0200
@@ -21,18 +21,53 @@ along with this program. If not, see <h
#include "smsspicommon.h"
#include "smsdbg_prn.h"
-static int smsspi_common_find_msg(struct _spi_dev *dev,
+static struct _rx_buffer_st *smsspi_handle_unused_bytes_buf(
+ struct _spi_dev *dev,
struct _rx_buffer_st *buf, int offset, int len,
- int *unused_bytes)
+ int unused_bytes)
{
- int i, missing_bytes;
+ struct _rx_buffer_st *tmp_buf;
+ tmp_buf = dev->cb.allocate_rx_buf(dev->context,
+ RX_PACKET_SIZE);
+ if (!tmp_buf) {
+ PRN_ERR((TXT
+ ("Failed to allocate RX buffer.\n")));
+ return NULL;
+ }
+ if (unused_bytes > 0) {
+ /* Copy the remaining bytes to the end of
+ alignment block (256 bytes) so next read
+ will be aligned. */
+ int align_block =
+ (((unused_bytes + SPI_PACKET_SIZE -
+ 1) >> SPI_PACKET_SIZE_BITS) <<
+ SPI_PACKET_SIZE_BITS);
+ memset(tmp_buf->ptr, 0,
+ align_block - unused_bytes);
+ memcpy((char *)tmp_buf->ptr +
+ (align_block - unused_bytes),
+ (char *)buf->ptr + offset + len -
+ unused_bytes, unused_bytes);
+ }
+ return tmp_buf;
+}
+
+static struct _rx_buffer_st *smsspi_common_find_msg(struct _spi_dev *dev,
+ struct _rx_buffer_st *buf, int offset, int len,
+ int *unused_bytes, int *missing_bytes)
+{
+ int i;
int recieved_bytes, padded_msg_len;
int align_fix;
int msg_offset;
- unsigned char *ptr = (unsigned char *)buf->ptr + offset;
+ char *ptr = (char *)buf->ptr + offset;
+ if (unused_bytes == NULL || missing_bytes == NULL)
+ return NULL;
+
+ *missing_bytes = 0;
+ *unused_bytes = 0;
PRN_DBG((TXT("entering with %d bytes.\n"), len));
- missing_bytes = 0;
for (i = 0; i < len; i++, ptr++) {
switch (dev->rxState) {
case RxsWait_a5:
@@ -104,7 +139,9 @@ static int smsspi_common_find_msg(struct
SPI_PACKET_SIZE_BITS;
if (recieved_bytes < padded_msg_len) {
*unused_bytes = 0;
- return padded_msg_len - recieved_bytes;
+ *missing_bytes = padded_msg_len -
+ recieved_bytes;
+ return buf;
}
dev->rxState = RxsWait_a5;
if (dev->cb.msg_found_cb) {
@@ -114,10 +151,11 @@ static int smsspi_common_find_msg(struct
align_fix =
(dev->rxPacket.
msg_flags >> 8) & 0x3;
- /* The FW aligned the message data therefore -
- * alignment bytes should be thrown away.
- * Throw the alignment bytes by moving the
- * header ahead over the alignment bytes. */
+ /* The FW aligned the message data
+ therefore - alignment bytes should be
+ thrown away. Throw the alignment bytes
+ by moving the header ahead over the
+ alignment bytes. */
if (align_fix) {
int length;
ptr =
@@ -150,30 +188,41 @@ static int smsspi_common_find_msg(struct
("Msg found and sent to callback func.\n")));
/* force all messages to start on
- 4-byte boundary */
+ * 4-byte boundary */
msg_offset = dev->rxPacket.msg_offset;
- if (msg_offset & 0x3) {
+ if (msg_offset & 0x3) {
msg_offset &= (~0x3);
memmove((unsigned char *)
- (dev->rxPacket.msg_buf->ptr) +
- msg_offset,
+ (dev->rxPacket.msg_buf->ptr)
+ + msg_offset,
(unsigned char *)
- (dev->rxPacket.msg_buf->ptr) +
- dev->rxPacket.msg_offset,
+ (dev->rxPacket.msg_buf->ptr)
+ + dev->rxPacket.msg_offset,
dev->rxPacket.msg_len -
align_fix);
}
+
+ *unused_bytes =
+ len + offset - dev->rxPacket.msg_offset -
+ dev->rxPacket.msg_len;
+
+ /* In any case we got here - unused_bytes
+ * should not be 0 Because we want to force
+ * reading at least 256 after the end
+ * of any found message */
+ if (*unused_bytes == 0)
+ *unused_bytes = -1;
+
+ buf = smsspi_handle_unused_bytes_buf(dev, buf,
+ offset, len, *unused_bytes);
+
dev->cb.msg_found_cb(dev->context,
dev->rxPacket.msg_buf,
msg_offset,
dev->rxPacket.msg_len -
align_fix);
- *unused_bytes =
- len + offset - dev->rxPacket.msg_offset -
- dev->rxPacket.msg_len;
- if (*unused_bytes == 0)
- *unused_bytes = -1;
- return 0;
+ *missing_bytes = 0;
+ return buf;
} else {
PRN_DBG((TXT
("Msg found but no callback. therefore - thrown away.\n")));
@@ -185,7 +234,8 @@ static int smsspi_common_find_msg(struct
if (dev->rxState == RxsWait_a5) {
*unused_bytes = 0;
- return 0;
+ *missing_bytes = 0;
+ return buf;
} else {
/* Workaround to corner case: if the last byte of the buffer
is "a5" (first byte of the preamble), the host thinks it should
@@ -195,22 +245,28 @@ static int smsspi_common_find_msg(struct
if ((dev->rxState == RxsWait_5a) && (*(ptr - 2) == 0xa5)) {
dev->rxState = RxsWait_a5;
*unused_bytes = 0;
- return 0;
+ *missing_bytes = 0;
+ return buf;
}
if (dev->rxPacket.msg_offset >= (SPI_PACKET_SIZE + 4))
/* adding 4 for the preamble. */
{ /*The packet will be copied to a new buffer
and rescaned by the state machine */
+ struct _rx_buffer_st *tmp_buf = buf;
*unused_bytes = dev->rxState - RxsWait_a5;
+ tmp_buf = smsspi_handle_unused_bytes_buf(dev, buf,
+ offset, len, *unused_bytes);
dev->rxState = RxsWait_a5;
dev->cb.free_rx_buf(dev->context, buf);
- return 0;
+ *missing_bytes = 0;
+ return tmp_buf;
} else {
/* report missing bytes and continue
with message scan. */
*unused_bytes = 0;
- return SPI_PACKET_SIZE;
+ *missing_bytes = SPI_PACKET_SIZE;
+ return buf;
}
}
}
@@ -263,14 +319,15 @@ void smsspi_common_transfer_msg(struct _
len = min(bytes_to_transfer, RX_PACKET_SIZE);
PRN_DBG((TXT("transfering block of %d bytes\n"), len));
dev->cb.transfer_data_cb(dev->phy_context,
- (unsigned char *)txbuf,
- tx_phy_addr,
- (unsigned char *)buf->ptr + offset,
- buf->phy_addr + offset, len);
+ (unsigned char *)txbuf,
+ tx_phy_addr,
+ (unsigned char *)buf->ptr + offset,
+ buf->phy_addr + offset, len);
}
- missing_bytes =
+
+ tmp_buf =
smsspi_common_find_msg(dev, buf, offset, len,
- &unused_bytes);
+ &unused_bytes, &missing_bytes);
if (bytes_to_transfer)
bytes_to_transfer -= len;
@@ -281,28 +338,14 @@ void smsspi_common_transfer_msg(struct _
offset += len;
if (unused_bytes) {
- tmp_buf =
- dev->cb.allocate_rx_buf(dev->context,
- RX_PACKET_SIZE);
- if (!tmp_buf) {
- PRN_ERR((TXT
- ("Failed to allocate RX buffer.\n")));
- return;
- }
+ /* In this case tmp_buf is a new buffer allocated
+ * in smsspi_common_find_msg
+ * and it already contains the unused bytes */
if (unused_bytes > 0) {
- /* Copy the remaining bytes to the end of
- alingment block (256 bytes) so next read
- will be alligned. */
align_block =
(((unused_bytes + SPI_PACKET_SIZE -
1) >> SPI_PACKET_SIZE_BITS) <<
SPI_PACKET_SIZE_BITS);
- memset(tmp_buf->ptr, 0,
- align_block - unused_bytes);
- memcpy((char *)tmp_buf->ptr +
- (align_block - unused_bytes),
- (char *)buf->ptr + offset + len -
- unused_bytes, unused_bytes);
len = align_block;
}
offset = 0;
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