[ 142/143] floppy: ignore kernel-only members in FDRAWCMD ioctl input

Willy Tarreau
2014-05-12T01:41:57Z

From: Matthew Daley <mattd@bugfuzz.com>

Always clear out these floppy_raw_cmd struct members after copying the
entire structure from userspace so that the in-kernel version is always
valid and never left in an interdeterminate state.

Signed-off-by: Matthew Daley <mattd@bugfuzz.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
(cherry picked from commit ef87dbe7614341c2e7bfe8d32fcb7028cc97442c)
[wt: be careful in 2.6.32 we still have the ugly macros everywhere]
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
drivers/block/floppy.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 5c01f74..19d45e6 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3209,9 +3209,12 @@ static inline int raw_cmd_copyin(int cmd, char __user *param,
if (!ptr)
return -ENOMEM;
*rcmd = ptr;
- COPYIN(*ptr);
+ ret = copy_from_user(ptr, (void __user *)param, sizeof(*ptr));
ptr->next = NULL;
ptr->buffer_length = 0;
+ ptr->kernel_data = NULL;
+ if (ret)
+ return -EFAULT;
param += sizeof(struct floppy_raw_cmd);
if (ptr->cmd_count > 33)
/* the command may now also take up the space
--
1.7.12.2.21.g234cd45.dirty