{"id":"CVE-2025-39987","summary":"can: hi311x: populate ndo_change_mtu() to prevent buffer overflow","details":"In the Linux kernel, the following vulnerability has been resolved:\n\ncan: hi311x: 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-\u003elen fits the interface's MTU.\n\nUnfortunately, because the sun4i_can driver does not populate its\nnet_device_ops-\u003endo_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-\u003eprotocol 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, hi3110_hard_start_xmit() receives a CAN XL frame which it is\nnot able to correctly handle and will thus misinterpret it as a CAN\nframe. The driver will consume frame-\u003elen as-is with no further\nchecks.\n\nThis can result in a buffer overflow later on in hi3110_hw_tx() on\nthis line:\n\n\tmemcpy(buf + HI3110_FIFO_EXT_DATA_OFF,\n\t       frame-\u003edata, frame-\u003elen);\n\nHere, frame-\u003elen corresponds to the flags field of the CAN XL frame.\nIn our previous example, we set canxl_frame-\u003eflags to 0xff. Because\nthe maximum expected length is 8, a buffer overflow of 247 bytes\noccurs!\n\nPopulate net_device_ops-\u003endo_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.","modified":"2026-03-20T12:43:07.788700Z","published":"2025-10-15T07:56:05.878Z","related":["MGASA-2025-0309","MGASA-2025-0310","SUSE-SU-2025:21040-1","SUSE-SU-2025:21052-1","SUSE-SU-2025:21056-1","SUSE-SU-2025:21064-1","SUSE-SU-2025:21080-1","SUSE-SU-2025:21147-1","SUSE-SU-2025:21180-1","SUSE-SU-2025:4057-1","SUSE-SU-2025:4128-1","SUSE-SU-2025:4132-1","SUSE-SU-2025:4140-1","SUSE-SU-2025:4141-1","SUSE-SU-2025:4301-1","openSUSE-SU-2025:20091-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39987.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/57d332ce8c921d0e340650470bb0c1d707f216ee"},{"type":"WEB","url":"https://git.kernel.org/stable/c/7ab85762274c0fa997f0ef9a2307b2001aae43c4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8f351db6b2367991f0736b2cff082f5de4872113"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ac1c7656fa717f29fac3ea073af63f0b9919ec9a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/be1b25005fd0f9d4e78bec6695711ef87ee33398"},{"type":"WEB","url":"https://git.kernel.org/stable/c/def814b4ba31b563584061d6895d5ff447d5bc14"},{"type":"WEB","url":"https://git.kernel.org/stable/c/e77fdf9e33a83a08f04ab0cb68c19ddb365a622f"},{"type":"WEB","url":"https://git.kernel.org/stable/c/f2c247e9581024d8b3dd44cbe086bf2bebbef42c"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/39xxx/CVE-2025-39987.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-39987"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"57e83fb9b7468c75cb65cde1d23043553c346c6d"},{"fixed":"f2c247e9581024d8b3dd44cbe086bf2bebbef42c"},{"fixed":"8f351db6b2367991f0736b2cff082f5de4872113"},{"fixed":"7ab85762274c0fa997f0ef9a2307b2001aae43c4"},{"fixed":"57d332ce8c921d0e340650470bb0c1d707f216ee"},{"fixed":"be1b25005fd0f9d4e78bec6695711ef87ee33398"},{"fixed":"def814b4ba31b563584061d6895d5ff447d5bc14"},{"fixed":"e77fdf9e33a83a08f04ab0cb68c19ddb365a622f"},{"fixed":"ac1c7656fa717f29fac3ea073af63f0b9919ec9a"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39987.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.12.0"},{"fixed":"5.4.300"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.10.245"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.194"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.155"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.109"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.50"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.16.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-39987.json"}}],"schema_version":"1.7.5"}