4.14-stable patches

[thirdparty/kernel/stable-queue.git] / releases / 3.10.40 / floppy-don-t-write-kernel-only-members-to-fdrawcmd-ioctl-output.patch

From 2145e15e0557a01b9195d1c7199a1b92cb9be81f Mon Sep 17 00:00:00 2001
From: Matthew Daley <mattd@bugfuzz.com>
Date: Mon, 28 Apr 2014 19:05:21 +1200
Subject: floppy: don't write kernel-only members to FDRAWCMD ioctl output

From: Matthew Daley <mattd@bugfuzz.com>

commit 2145e15e0557a01b9195d1c7199a1b92cb9be81f upstream.

Do not leak kernel-only floppy_raw_cmd structure members to userspace.
This includes the linked-list pointer and the pointer to the allocated
DMA space.

Signed-off-by: Matthew Daley <mattd@bugfuzz.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/block/floppy.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3053,7 +3053,10 @@ static int raw_cmd_copyout(int cmd, void
 	int ret;
 
 	while (ptr) {
-		ret = copy_to_user(param, ptr, sizeof(*ptr));
+		struct floppy_raw_cmd cmd = *ptr;
+		cmd.next = NULL;
+		cmd.kernel_data = NULL;
+		ret = copy_to_user(param, &cmd, sizeof(cmd));
 		if (ret)
 			return -EFAULT;
 		param += sizeof(struct floppy_raw_cmd);