lkml.org 
[lkml]   [2022]   [Feb]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH 5.10 45/80] spi: spi-zynq-qspi: Fix a NULL pointer dereference in zynq_qspi_exec_mem_op()
Date
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;
--
2.34.1


\
 
 \ /
  Last update: 2022-02-28 18:45    [W:1.158 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site