From: Len Baker
> Sent: 18 July 2021 12:32
>
> strcpy() performs no bounds checking on the destination buffer. This
> could result in linear overflows beyond the end of the buffer, leading
> to all kinds of misbehaviors. The safe replacement is strscpy().
>
> Signed-off-by: Len Baker <len.baker@xxxxxxx>
> ---
> drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
> b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
> index ab885353f668..1a193f900779 100644
> --- a/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
> +++ b/drivers/staging/rtl8192u/ieee80211/ieee80211_softmac.c
> @@ -2226,7 +2226,8 @@ static void ieee80211_start_ibss_wq(struct work_struct *work)
> mutex_lock(&ieee->wx_mutex);
>
> if (ieee->current_network.ssid_len == 0) {
> - strcpy(ieee->current_network.ssid, IEEE80211_DEFAULT_TX_ESSID);
> + strscpy(ieee->current_network.ssid, IEEE80211_DEFAULT_TX_ESSID,
> + sizeof(ieee->current_network.ssid));
I'm pretty sure that recent compiler releases know enough
about strcpy() to error overflows for strcpy() from quoted
strings into char[].
If these checks are enabled for kernel builds then they are
actually safer than the run-time check above
(which can be mistyped).
The compiler can (it may not) convert the strcpy() into a memcpy()
using the compile-time length of the quoted string.
David
-
Registered Address Lakeside, Bramley Road, Mount Farm, Milton Keynes, MK1 1PT, UK
Registration No: 1397386 (Wales)
