[PATCH 3/3] dmaengine: xilinx: dpdma: Reserve space for a string terminator

[Jiale Yao]

xilinx_dpdma_debugfs_write() allocates a buffer of size bytes, and
strncpy_from_user() can fill it without a terminating NUL when the input
has no NUL in the copied range. strsep() and strcasecmp() then read
beyond the buffer.

Allocate an extra byte and keep that byte zero-initialized, so the input
copied remains unchanged and the buffer is always terminated.

Fixes: 1d220435cab3 ("dmaengine: xilinx: dpdma: Add debugfs support")
Signed-off-by: Jiale Yao <yaojiale02@xxxxxxx>
---
 drivers/dma/xilinx/xilinx_dpdma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/dma/xilinx/xilinx_dpdma.c b/drivers/dma/xilinx/xilinx_dpdma.c
index d9a3542c4531..b61ef3062d84 100644
--- a/drivers/dma/xilinx/xilinx_dpdma.c
+++ b/drivers/dma/xilinx/xilinx_dpdma.c
@@ -410,7 +410,7 @@ static ssize_t xilinx_dpdma_debugfs_write(struct file *f,
 	if (dpdma_debugfs.testcase != DPDMA_TC_NONE)
 		return -EBUSY;
 
-	kern_buff = kzalloc(size, GFP_KERNEL);
+	kern_buff = kzalloc(size + 1, GFP_KERNEL);
 	if (!kern_buff)
 		return -ENOMEM;
 	kern_buff_start = kern_buff;
-- 
2.34.1