From: Matthew Daley <mattd@bugfuzz.com>
Date: Mon, 28 Apr 2014 07:05:21 +0000 (+1200)
Subject: floppy: don't write kernel-only members to FDRAWCMD ioctl output
X-Git-Tag: firefly_0821_release~3679^2~2383
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=50c648e394a0968f19d448b70bec82da88219963;p=firefly-linux-kernel-4.4.55.git

floppy: don't write kernel-only members to FDRAWCMD ioctl output

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>
---

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 1a8ab67d1651..eb3575b3fbf0 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3053,7 +3053,10 @@ static int raw_cmd_copyout(int cmd, void __user *param,
 	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);