diff options
| author | Harry Morris <h.morris@cascoda.com> | 2018-03-28 11:54:27 +0100 |
|---|---|---|
| committer | Stefan Schmidt <stefan@osg.samsung.com> | 2018-03-29 16:51:26 +0200 |
| commit | 86674a97f5055f4c7f406563408096e8cf9364ff (patch) | |
| tree | ee99af9a7443c785412b163b350ba9e309e44760 | |
| parent | 8fd4bc8a15b218165c45f44eba1b33a3c7181dfb (diff) | |
ieee802154: ca8210: fix uninitialised data read
In ca8210_test_int_user_write() a user can request the transfer of a
frame with a length field (command.length) that is longer than the
actual buffer provided (len). In this scenario the driver will copy
the buffer contents into the uninitialised command[] buffer, then
transfer <data.length> bytes over the SPI even though only <len> bytes
had been populated, potentially leaking sensitive kernel memory.
Also the first 6 bytes of the command buffer must be initialised in case
a malformed, short packet is written and the uninitialised bytes are
read in ca8210_test_check_upstream.
Reported-by: Domen Puncer Kugler <domen.puncer@samsung.com>
Signed-off-by: Harry Morris <h.morris@cascoda.com>
Tested-by: Harry Morris <h.morris@cascoda.com>
Signed-off-by: Stefan Schmidt <stefan@osg.samsung.com>
| -rw-r--r-- | drivers/net/ieee802154/ca8210.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/drivers/net/ieee802154/ca8210.c b/drivers/net/ieee802154/ca8210.c index 377af43b81b3..58299fb666ed 100644 --- a/drivers/net/ieee802154/ca8210.c +++ b/drivers/net/ieee802154/ca8210.c @@ -2493,13 +2493,14 @@ static ssize_t ca8210_test_int_user_write( struct ca8210_priv *priv = filp->private_data; u8 command[CA8210_SPI_BUF_SIZE]; - if (len > CA8210_SPI_BUF_SIZE) { + memset(command, SPI_IDLE, 6); + if (len > CA8210_SPI_BUF_SIZE || len < 2) { dev_warn( &priv->spi->dev, - "userspace requested erroneously long write (%zu)\n", + "userspace requested erroneous write length (%zu)\n", len ); - return -EMSGSIZE; + return -EBADE; } ret = copy_from_user(command, in_buf, len); @@ -2511,6 +2512,13 @@ static ssize_t ca8210_test_int_user_write( ); return -EIO; } + if (len != command[1] + 2) { + dev_err( + &priv->spi->dev, + "write len does not match packet length field\n" + ); + return -EBADE; + } ret = ca8210_test_check_upstream(command, priv->spi); if (ret == 0) { |