From: Zhou Qingyang zhou1615@umn.edu
[ Upstream commit ab3824427b848da10e9fe2727f035bbeecae6ff4 ]
In zynq_qspi_exec_mem_op(), kzalloc() is directly used in memset(), which could lead to a NULL pointer dereference on failure of kzalloc().
Fix this bug by adding a check of tmpbuf.
This bug was found by a static analyzer. The analysis employs differential checking to identify inconsistent security operations (e.g., checks or kfrees) between two code paths and confirms that the inconsistent operations are not recovered in the current function or the callers, so they constitute bugs.
Note that, as a bug found by static analysis, it can be a false positive or hard to trigger. Multiple researchers have cross-reviewed the bug.
Builds with CONFIG_SPI_ZYNQ_QSPI=m show no new warnings, and our static analyzer no longer warns about this code.
Fixes: 67dca5e580f1 ("spi: spi-mem: Add support for Zynq QSPI controller") Signed-off-by: Zhou Qingyang zhou1615@umn.edu Link: https://lore.kernel.org/r/20211130172253.203700-1-zhou1615@umn.edu Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-zynq-qspi.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c index b635835729d66..13c0b15fe1764 100644 --- a/drivers/spi/spi-zynq-qspi.c +++ b/drivers/spi/spi-zynq-qspi.c @@ -570,6 +570,9 @@ static int zynq_qspi_exec_mem_op(struct spi_mem *mem,
if (op->dummy.nbytes) { tmpbuf = kzalloc(op->dummy.nbytes, GFP_KERNEL); + if (!tmpbuf) + return -ENOMEM; + memset(tmpbuf, 0xff, op->dummy.nbytes); reinit_completion(&xqspi->data_completion); xqspi->txbuf = tmpbuf;