Re: [ 097/184] Bluetooth: Fix incorrect strncpy() in

[Ben Hutchings]

On Tue, 2013-06-04 at 19:23 +0200, Willy Tarreau wrote:
> 2.6.32-longterm review patch.  If anyone has any objections, please let me know.
> 
> ------------------
>  hidp_setup_hid()
> 
> From: Anderson Lizardo <anderson.lizardo@xxxxxxxxxxxxx>

This is missing the upstream reference.  It was commit
0a9ab9bdb3e891762553f667066190c1d22ad62b.

Ben.

> The length parameter should be sizeof(req->name) - 1 because there is no
> guarantee that string provided by userspace will contain the trailing
> '\0'.
> 
> Can be easily reproduced by manually setting req->name to 128 non-zero
> bytes prior to ioctl(HIDPCONNADD) and checking the device name setup on
> input subsystem:
> 
> $ cat /sys/devices/pnp0/00\:04/tty/ttyS0/hci0/hci0\:1/input8/name
> AAAAAA[...]AAAAAAAAf0:af:f0:af:f0:af
> 
> ("f0:af:f0:af:f0:af" is the device bluetooth address, taken from "phys"
> field in struct hid_device due to overflow.)
> 
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Anderson Lizardo <anderson.lizardo@xxxxxxxxxxxxx>
> Acked-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
> Signed-off-by: Gustavo Padovan <gustavo.padovan@xxxxxxxxxxxxxxx>
> 
> [backported to 2.6.32 jmm]
> Signed-off-by: Willy Tarreau <w@xxxxxx>
> ---
>  net/bluetooth/hidp/core.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/net/bluetooth/hidp/core.c b/net/bluetooth/hidp/core.c
> index 49d8495..0c2c59d 100644
> --- a/net/bluetooth/hidp/core.c
> +++ b/net/bluetooth/hidp/core.c
> @@ -778,7 +778,7 @@ static int hidp_setup_hid(struct hidp_session *session,
>  	hid->version = req->version;
>  	hid->country = req->country;
>  
> -	strncpy(hid->name, req->name, 128);
> +	strncpy(hid->name, req->name, sizeof(req->name) - 1);
>  	strncpy(hid->phys, batostr(&src), 64);
>  	strncpy(hid->uniq, batostr(&dst), 64);
>  

-- 
Ben Hutchings
Theory and practice are closer in theory than in practice.
                                - John Levine, moderator of comp.compilers

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