diff options
| author | Tobi Gaertner <tob.gaertner@me.com> | 2026-03-14 08:46:40 +0300 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2026-03-17 06:14:48 +0300 |
| commit | 77914255155e68a20aa41175edeecf8121dac391 (patch) | |
| tree | 9cf3795ce1622db170ef44043cc39ee3de55e13d | |
| parent | 2aa8a4fa8d5b7d0e1ebcec100e1a4d80a1f4b21a (diff) | |
| download | linux-77914255155e68a20aa41175edeecf8121dac391.tar.xz | |
net: usb: cdc_ncm: add ndpoffset to NDP32 nframes bounds check
The same bounds-check bug fixed for NDP16 in the previous patch also
exists in cdc_ncm_rx_verify_ndp32(). The DPE array size is validated
against the total skb length without accounting for ndpoffset, allowing
out-of-bounds reads when the NDP32 is placed near the end of the NTB.
Add ndpoffset to the nframes bounds check and use struct_size_t() to
express the NDP-plus-DPE-array size more clearly.
Compile-tested only.
Fixes: 0fa81b304a79 ("cdc_ncm: Implement the 32-bit version of NCM Transfer Block")
Signed-off-by: Tobi Gaertner <tob.gaertner@me.com>
Link: https://patch.msgid.link/20260314054640.2895026-3-tob.gaertner@me.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| -rw-r--r-- | drivers/net/usb/cdc_ncm.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 21e53b20e239..bb9929727eb9 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -1693,6 +1693,7 @@ int cdc_ncm_rx_verify_ndp32(struct sk_buff *skb_in, int ndpoffset) struct usbnet *dev = netdev_priv(skb_in->dev); struct usb_cdc_ncm_ndp32 *ndp32; int ret = -EINVAL; + size_t ndp_len; if ((ndpoffset + sizeof(struct usb_cdc_ncm_ndp32)) > skb_in->len) { netif_dbg(dev, rx_err, dev->net, "invalid NDP offset <%u>\n", @@ -1712,8 +1713,8 @@ int cdc_ncm_rx_verify_ndp32(struct sk_buff *skb_in, int ndpoffset) sizeof(struct usb_cdc_ncm_dpe32)); ret--; /* we process NDP entries except for the last one */ - if ((sizeof(struct usb_cdc_ncm_ndp32) + - ret * (sizeof(struct usb_cdc_ncm_dpe32))) > skb_in->len) { + ndp_len = struct_size_t(struct usb_cdc_ncm_ndp32, dpe32, ret); + if (ndpoffset + ndp_len > skb_in->len) { netif_dbg(dev, rx_err, dev->net, "Invalid nframes = %d\n", ret); ret = -EINVAL; } |