{"resultsPerPage":1,"startIndex":0,"totalResults":1,"format":"NVD_CVE","version":"2.0","timestamp":"2026-05-06T07:26:27.429","vulnerabilities":[{"cve":{"id":"CVE-2025-39986","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","published":"2025-10-15T08:15:36.653","lastModified":"2026-04-15T00:35:42.020","vulnStatus":"Deferred","cveTags":[],"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: sun4i_can: populate ndo_change_mtu() to prevent buffer overflow\n\nSending an PF_PACKET allows to bypass the CAN framework logic and to\ndirectly reach the xmit() function of a CAN driver. The only check\nwhich is performed by the PF_PACKET framework is to make sure that\nskb->len fits the interface's MTU.\n\nUnfortunately, because the sun4i_can driver does not populate its\nnet_device_ops->ndo_change_mtu(), it is possible for an attacker to\nconfigure an invalid MTU by doing, for example:\n\n  $ ip link set can0 mtu 9999\n\nAfter doing so, the attacker could open a PF_PACKET socket using the\nETH_P_CANXL protocol:\n\n\tsocket(PF_PACKET, SOCK_RAW, htons(ETH_P_CANXL))\n\nto inject a malicious CAN XL frames. For example:\n\n\tstruct canxl_frame frame = {\n\t\t.flags = 0xff,\n\t\t.len = 2048,\n\t};\n\nThe CAN drivers' xmit() function are calling can_dev_dropped_skb() to\ncheck that the skb is valid, unfortunately under above conditions, the\nmalicious packet is able to go through can_dev_dropped_skb() checks:\n\n  1. the skb->protocol is set to ETH_P_CANXL which is valid (the\n     function does not check the actual device capabilities).\n\n  2. the length is a valid CAN XL length.\n\nAnd so, sun4ican_start_xmit() receives a CAN XL frame which it is not\nable to correctly handle and will thus misinterpret it as a CAN frame.\n\nThis can result in a buffer overflow. The driver will consume cf->len\nas-is with no further checks on this line:\n\n\tdlc = cf->len;\n\nHere, cf->len corresponds to the flags field of the CAN XL frame. In\nour previous example, we set canxl_frame->flags to 0xff. Because the\nmaximum expected length is 8, a buffer overflow of 247 bytes occurs a\ncouple line below when doing:\n\n\tfor (i = 0; i < dlc; i++)\n\t\twritel(cf->data[i], priv->base + (dreg + i * 4));\n\nPopulate net_device_ops->ndo_change_mtu() to ensure that the\ninterface's MTU can not be set to anything bigger than CAN_MTU. By\nfixing the root cause, this prevents the buffer overflow."}],"metrics":{},"references":[{"url":"https://git.kernel.org/stable/c/063539db42203b29d5aa2adf0cae3d68c646a6b6","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2e423e1990f3972cbea779883fef52c2f2acb858","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4f382cc887adca8478b9d3e6b81aa6698a95fff4","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/60463a1c138900494cb3adae41142a11cd8feb3c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/61da0bd4102c459823fbe6b8b43b01fb6ace4a22","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7f7b21026a6febdb749f6f6f950427245aa86cce","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a61ff7ac93270d20ca426c027d6d01c8ac8e904c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/de77841652e57afbc46e9e1dbf51ee364fc008e1","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}]}}]}