[precise,quantal,precise/lts-backport-raring,saucy,trusty,1/2] floppy: ignore kernel-only members in FDRAWCMD ioctl input
diff mbox

Message ID 1399403436-21214-5-git-send-email-apw@canonical.com
State New
Headers show

Commit Message

Andy Whitcroft May 6, 2014, 7:10 p.m. UTC
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)
CVE-2014-1737
BugLink: http://bugs.launchpad.net/bugs/1316729
Signed-off-by: Andy Whitcroft <apw@canonical.com>
---
 drivers/block/floppy.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Comments

Brad Figg June 16, 2014, 4:29 p.m. UTC | #1
On 05/06/2014 12:10 PM, Andy Whitcroft wrote:
> 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)
> CVE-2014-1737
> BugLink: http://bugs.launchpad.net/bugs/1316729
> Signed-off-by: Andy Whitcroft <apw@canonical.com>
> ---
>  drivers/block/floppy.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
> index 000abe2..10fbd3f 100644
> --- a/drivers/block/floppy.c
> +++ b/drivers/block/floppy.c
> @@ -3107,10 +3107,11 @@ loop:
>  		return -ENOMEM;
>  	*rcmd = ptr;
>  	ret = copy_from_user(ptr, param, sizeof(*ptr));
> -	if (ret)
> -		return -EFAULT;
>  	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
> @@ -3126,7 +3127,6 @@ loop:
>  	for (i = 0; i < 16; i++)
>  		ptr->reply[i] = 0;
>  	ptr->resultcode = 0;
> -	ptr->kernel_data = NULL;
>  
>  	if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) {
>  		if (ptr->length <= 0)
>

Patch
diff mbox

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 000abe2..10fbd3f 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -3107,10 +3107,11 @@  loop:
 		return -ENOMEM;
 	*rcmd = ptr;
 	ret = copy_from_user(ptr, param, sizeof(*ptr));
-	if (ret)
-		return -EFAULT;
 	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
@@ -3126,7 +3127,6 @@  loop:
 	for (i = 0; i < 16; i++)
 		ptr->reply[i] = 0;
 	ptr->resultcode = 0;
-	ptr->kernel_data = NULL;
 
 	if (ptr->flags & (FD_RAW_READ | FD_RAW_WRITE)) {
 		if (ptr->length <= 0)