Commit 45e1058b authored by Dan Carpenter's avatar Dan Carpenter Committed by Jon Mason
Browse files

NTB: ntb_tool: uninitialized heap data in tool_fn_write() 



The call to:

	ret = simple_write_to_buffer(buf, size, offp, ubuf, size);

will return success if it is able to write even one byte to "buf".
The value of "*offp" controls which byte.  This could result in
reading uninitialized data when we do the sscanf() on the next line.

This code is not really desigined to handle partial writes where
*offp is non-zero and the "buf" is preserved and re-used between writes.
Just ban partial writes and replace the simple_write_to_buffer() with
copy_from_user().

Fixes: 578b881b ("NTB: Add tool test client")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
parent a44252d5

drivers/ntb/test/ntb_tool.c

+5 −3
Original line number Diff line number Diff line
@@ -367,14 +367,16 @@ static ssize_t tool_fn_write(struct tool_ctx *tc, 
	u64 bits;

	int n;



	if (*offp)

		return 0;



	buf = kmalloc(size + 1, GFP_KERNEL);

	if (!buf)

		return -ENOMEM;



	ret = simple_write_to_buffer(buf, size, offp, ubuf, size);

	if (ret < 0) {

	if (copy_from_user(buf, ubuf, size)) {

		kfree(buf);

		return ret;

		return -EFAULT;

	}



	buf[size] = 0;