6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Guanglei Zhu commit c7ead9704249d57d4693a04697e3bbd285138fa9 upstream. The netif index carried in the DPMAIF PIT header is five bits wide, but ccmni_inst[] only has room for NIC_DEV_MAX (21) entries. t7xx_ccmni_recv_skb() indexes the array without a bounds check, so indexes 21 to 31 read past it. The out-of-bounds value lands in the callback table that follows the array, which is never NULL, so the existing !ccmni check does not catch it and the driver dereferences whatever sits there as a struct t7xx_ccmni. Drop the skb when the index is out of range. Fixes: 05d19bf500f8 ("net: wwan: t7xx: Add WWAN network interface") Cc: stable@vger.kernel.org Signed-off-by: Guanglei Zhu Signed-off-by: Greg Kroah-Hartman Verified in a QEMU guest with a fault injector setting the netif index to 25: the unpatched driver reads a value past ccmni_inst[], which lands in the callback table, and dereferences it far enough to queue the skb. With this check the packet is dropped. Well-formed traffic on index 0 is unaffected. Changes in v2: none. Link: https://patch.msgid.link/20260911021734.1396599-3-zhugl3@xiaopeng.com Signed-off-by: Jakub Kicinski --- drivers/net/wwan/t7xx/t7xx_netdev.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/drivers/net/wwan/t7xx/t7xx_netdev.c +++ b/drivers/net/wwan/t7xx/t7xx_netdev.c @@ -414,6 +414,10 @@ static void t7xx_ccmni_recv_skb(struct t skb_cb = T7XX_SKB_CB(skb); netif_id = skb_cb->netif_idx; + if (netif_id >= NIC_DEV_MAX) { + dev_kfree_skb(skb); + return; + } ccmni = READ_ONCE(ccmni_ctlb->ccmni_inst[netif_id]); if (!ccmni) { dev_kfree_skb(skb);