| Message ID | 20250125235409.3106594-2-forst@pen.gy |
|---|---|
| State | New |
| Headers | show |
| Series | usbnet: ipheth: prevent OoB reads of NDP16 | expand |
diff --git a/drivers/net/usb/ipheth.c b/drivers/net/usb/ipheth.c index 46afb95ffabe..45daae234cb8 100644 --- a/drivers/net/usb/ipheth.c +++ b/drivers/net/usb/ipheth.c @@ -243,8 +243,8 @@ static int ipheth_rcvbulk_callback_ncm(struct urb *urb) while (le16_to_cpu(dpe->wDatagramIndex) != 0 && le16_to_cpu(dpe->wDatagramLength) != 0) { if (le16_to_cpu(dpe->wDatagramIndex) >= urb->actual_length || - le16_to_cpu(dpe->wDatagramIndex) + - le16_to_cpu(dpe->wDatagramLength) > urb->actual_length) { + le16_to_cpu(dpe->wDatagramLength) > urb->actual_length - + le16_to_cpu(dpe->wDatagramIndex)) { dev->net->stats.rx_length_errors++; return retval; }
Originally, it was possible for the DPE length check to overflow if wDatagramIndex + wDatagramLength > U16_MAX. This could lead to an OoB read. Move the wDatagramIndex term to the other side of the inequality. An existing condition ensures that wDatagramIndex < urb->actual_length. Fixes: a2d274c62e44 ("usbnet: ipheth: add CDC NCM support") Cc: stable@vger.kernel.org Signed-off-by: Foster Snowhill <forst@pen.gy> Reviewed-by: Jakub Kicinski <kuba@kernel.org> --- v5: No code changes. Added Cc to stable and Reviewed-by Jakub tags. v4: https://lore.kernel.org/netdev/20250105010121.12546-3-forst@pen.gy/ No change since v3. v3: https://lore.kernel.org/netdev/20241123235432.821220-2-forst@pen.gy/ Split out from a monolithic patch in v2 as an atomic change. v2: https://lore.kernel.org/netdev/20240912211817.1707844-1-forst@pen.gy/ No code changes. Update commit message to further clarify that `ipheth` is not and does not aim to be a complete or spec-compliant CDC NCM implementation. v1: https://lore.kernel.org/netdev/20240907230108.978355-1-forst@pen.gy/ --- drivers/net/usb/ipheth.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)