From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:59847) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1eeT2k-0007L1-Ok for qemu-devel@nongnu.org; Wed, 24 Jan 2018 16:57:19 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1eeT2h-0005iy-Nf for qemu-devel@nongnu.org; Wed, 24 Jan 2018 16:57:18 -0500 Received: from mail-lf0-x244.google.com ([2a00:1450:4010:c07::244]:33948) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1eeT2h-0005hb-GS for qemu-devel@nongnu.org; Wed, 24 Jan 2018 16:57:15 -0500 Received: by mail-lf0-x244.google.com with SMTP id k19so7185872lfj.1 for ; Wed, 24 Jan 2018 13:57:14 -0800 (PST) From: Francisco Iglesias Date: Wed, 24 Jan 2018 22:57:08 +0100 Message-Id: <20180124215708.30400-1-frasse.iglesias@gmail.com> Subject: [Qemu-devel] [PATCH v3] xilinx_spips: Correct usage of an uninitialized local variable List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: edgari@xilinx.com, alistai@xilinx.com, francisco.iglesias@feimtech.se, peter.maydell@linaro.org Coverity found that the variable tx_rx in the function xilinx_spips_flush_txfifo was being used uninitialized (CID 1383841). This patch corrects this by always initializing tx_rx to zeros. Signed-off-by: Francisco Iglesias --- v3. Change to report errors on the num_busses property via the Error** parameter when realizing the devices. --- v2. Add a sanity check on the num_busses property when realizing the devices. --- hw/ssi/xilinx_spips.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/hw/ssi/xilinx_spips.c b/hw/ssi/xilinx_spips.c index 85c5d0c..8af36ca 100644 --- a/hw/ssi/xilinx_spips.c +++ b/hw/ssi/xilinx_spips.c @@ -210,6 +210,9 @@ #define SNOOP_NONE 0xEE #define SNOOP_STRIPING 0 +#define MIN_NUM_BUSSES 1 +#define MAX_NUM_BUSSES 2 + static inline int num_effective_busses(XilinxSPIPS *s) { return (s->regs[R_LQSPI_CFG] & LQSPI_CFG_SEP_BUS && @@ -573,7 +576,7 @@ static void xilinx_spips_flush_txfifo(XilinxSPIPS *s) for (;;) { int i; uint8_t tx = 0; - uint8_t tx_rx[num_effective_busses(s)]; + uint8_t tx_rx[MAX_NUM_BUSSES] = { 0 }; uint8_t dummy_cycles = 0; uint8_t addr_length; @@ -1221,6 +1224,19 @@ static void xilinx_spips_realize(DeviceState *dev, Error **errp) DB_PRINT_L(0, "realized spips\n"); + if (s->num_busses > MAX_NUM_BUSSES) { + error_setg(errp, + "requested number of SPI busses %u exceeds maximum %d", + s->num_busses, MAX_NUM_BUSSES); + return; + } + if (s->num_busses < MIN_NUM_BUSSES) { + error_setg(errp, + "requested number of SPI busses %u is below minimum %d", + s->num_busses, MIN_NUM_BUSSES); + return; + } + s->spi = g_new(SSIBus *, s->num_busses); for (i = 0; i < s->num_busses; ++i) { char bus_name[16]; -- 2.9.3