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authorZhou Qingyang <zhou1615@umn.edu>2021-11-30 20:22:53 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2022-03-02 13:41:10 +0300
commitdf14d2bed8e2455878e046e67123d9ecb2e79056 (patch)
tree6c7eb412f2478d55063fdd378e8ae992535a3a42
parenta62f4266d572357a9d93a6c9579c265dac8cdd66 (diff)
downloadlinux-df14d2bed8e2455878e046e67123d9ecb2e79056.tar.xz
spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op()
[ 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>
-rw-r--r--drivers/spi/spi-zynq-qspi.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/spi/spi-zynq-qspi.c b/drivers/spi/spi-zynq-qspi.c
index 1ced6eb8b330..b3588240eb39 100644
--- a/drivers/spi/spi-zynq-qspi.c
+++ b/drivers/spi/spi-zynq-qspi.c
@@ -558,6 +558,9 @@ 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;