4.14-stable review patch. If anyone has any objections, please let me know.
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From: Harry Morris h.morris@cascoda.com
[ Upstream commit 86674a97f5055f4c7f406563408096e8cf9364ff ]
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 Signed-off-by: Sasha Levin alexander.levin@microsoft.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ieee802154/ca8210.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
--- a/drivers/net/ieee802154/ca8210.c +++ b/drivers/net/ieee802154/ca8210.c @@ -2493,13 +2493,14 @@ static ssize_t ca8210_test_int_user_writ 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_writ ); 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) {