[PATCH 3.14 06/83] floppy: dont write kernel-only members to FDRAWCMD ioctl output

Greg Kroah-Hartman
2014-05-11T19:20:50Z

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);