On 5/18/22 11:00, Denis Efremov wrote:
This code has a check to prevent read overflow but it needs another check to prevent writing beyond the end of the ->Ssid[] array.
Fixes: 2b42bd58b321 ("staging: r8188eu: introduce new os_dep dir for RTL8188eu driver") Cc: stable stable@vger.kernel.org Signed-off-by: Denis Efremov denis.e.efremov@oracle.com
This patch is a copy of Dan's 74b6b20df8cf (CVE-2021-28660). Drivers r8188eu and rtl8188eu share the same code.
I also found same code pattern in rtl8723bs driver in stable kernels 5.10, 5.4, 4.19, 4.14. https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/driver... I can send the same fix to stable trees if appropriate.
drivers/staging/r8188eu/os_dep/ioctl_linux.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/r8188eu/os_dep/ioctl_linux.c b/drivers/staging/r8188eu/os_dep/ioctl_linux.c index eb9375b0c660..a2692ce02bc2 100644 --- a/drivers/staging/r8188eu/os_dep/ioctl_linux.c +++ b/drivers/staging/r8188eu/os_dep/ioctl_linux.c @@ -1131,9 +1131,11 @@ static int rtw_wx_set_scan(struct net_device *dev, struct iw_request_info *a, break; } sec_len = *(pos++); len -= 1;
if (sec_len > 0 && sec_len <= len) {
if (sec_len > 0 &&sec_len <= len &&sec_len <= 32) { ssid[ssid_index].SsidLength = sec_len;
memcpy(ssid[ssid_index].Ssid, pos, ssid[ssid_index].SsidLength);
memcpy(ssid[ssid_index].Ssid, pos, sec_len); ssid_index++; } pos += sec_len;