{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-39988", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.150Z", "datePublished": "2025-10-15T07:56:06.601Z", "dateUpdated": "2026-08-05T12:06:55.862Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:06:55.862Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: etas_es58x: 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 etas_es58x 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, es58x_start_xmit() receives a CAN XL frame which it is not\nable to correctly handle and will thus misinterpret it as a CAN(FD)\nframe.\n\nThis can result in a buffer overflow. For example, using the es581.4\nvariant, the frame will be dispatched to es581_4_tx_can_msg(), go\nthrough the last check at the beginning of this function:\n\n\tif (can_is_canfd_skb(skb))\n\t\treturn -EMSGSIZE;\n\nand reach this line:\n\n\tmemcpy(tx_can_msg->data, cf->data, 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!\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 or\nCANFD_MTU (depending on the device capabilities). By fixing the root\ncause, this prevents the buffer overflow." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - Exploitation requires local syscalls on the host — creating a PF_PACKET/SOCK_RAW socket with ETH_P_CANXL and sendmsg() to the can interface (optionally preceded by an rtnetlink MTU change), with the frame reaching es58x_start_xmit() via dev_queue_xmit(). No remote or adjacent network peer can reach this path; the CAN bus itself is only the sink, not the source.\nAC:L - The overflow is fully deterministic: can_dropped_invalid_skb() accepts an ETH_P_CANXL skb on a non-XL device, es581_4_tx_can_msg()/es58x_fd_tx_can_msg() then reinterpret canxl_frame.flags as can_frame.len and memcpy() up to 255 attacker-chosen bytes into an 8-byte (or 64-byte) field. No race, no memory-layout guessing, and no condition outside the attacker's control is needed to trigger it.\nPR:L - The two gates are ns_capable(net->user_ns, CAP_NET_RAW) in packet_create() and ns_capable(CAP_NET_ADMIN) for the MTU change — both namespaced, and CAN netdevs are not netns-local, so a can0 delegated into a container/user namespace lets an otherwise unprivileged user hold both (CAP_NET_RAW is granted by default in typical container runtimes). No real root in the init namespace is required.\nUI:N - The attacker performs every step alone — bring the interface up, optionally set the MTU, open the packet socket and send the malicious CAN XL frame. No victim action or interaction is needed.\nS:U - The corruption stays within the kernel of the same host; there is no VM, IOMMU, or hypervisor boundary crossed. Impact and vulnerable component share one security authority.\nC:H - With a minimal skb (skb->len as low as 13–16 bytes, permitted even at the default CAN_MTU), memcpy() reads cf->len (up to 255) bytes from the small skb data area, over-reading adjacent kernel heap; that leaked memory is placed into the URB transfer buffer and DMA'd out to the USB device, giving a readable kernel-memory disclosure primitive.\nI:H - Up to 247 bytes of attacker-controlled data are written past the intended message slot; for the ES581.4 the TX buffer is a ~509-byte usb_alloc_coherent() allocation served from the HCD's shared 512-byte dma_pool, so the overflow lands in adjacent in-use DMA buffers belonging to other USB transfers — a controlled out-of-bounds write suitable for further corruption.\nA:H - Corrupting neighbouring USB DMA-pool blocks and pool metadata reliably produces kernel oops/panic or wedged USB transfers, and the overflow can be re-triggered at will from an unprivileged socket, so the whole system's availability is at stake." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/can/usb/etas_es58x/es58x_core.c" ], "versions": [ { "version": "8537257874e949a59c834cecfd5a063e11b64b0b", "lessThan": "72de0facc50afdb101fb7197d880407f1abfc77f", "status": "affected", "versionType": "git" }, { "version": "8537257874e949a59c834cecfd5a063e11b64b0b", "lessThan": "c4e582e686c4d683c87f2b4a316385b3d81d370f", "status": "affected", "versionType": "git" }, { "version": "8537257874e949a59c834cecfd5a063e11b64b0b", "lessThan": "cbc1de71766f326a44bb798aeae4a7ef4a081cc9", "status": "affected", "versionType": "git" }, { "version": "8537257874e949a59c834cecfd5a063e11b64b0b", "lessThan": "b26cccd87dcddc47b450a40f3b1ac3fe346efcff", "status": "affected", "versionType": "git" }, { "version": "8537257874e949a59c834cecfd5a063e11b64b0b", "lessThan": "e587af2c89ecc6382c518febea52fa9ba81e47c0", "status": "affected", "versionType": "git" }, { "version": "8537257874e949a59c834cecfd5a063e11b64b0b", "lessThan": "38c0abad45b190a30d8284a37264d2127a6ec303", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/can/usb/etas_es58x/es58x_core.c" ], "versions": [ { "version": "5.13", "status": "affected" }, { "version": "0", "lessThan": "5.13", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.194", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.155", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.109", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.50", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16.10", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "5.15.194" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.1.155" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.6.109" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.12.50" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.16.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.13", "versionEndExcluding": "6.17" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/72de0facc50afdb101fb7197d880407f1abfc77f" }, { "url": "https://git.kernel.org/stable/c/c4e582e686c4d683c87f2b4a316385b3d81d370f" }, { "url": "https://git.kernel.org/stable/c/cbc1de71766f326a44bb798aeae4a7ef4a081cc9" }, { "url": "https://git.kernel.org/stable/c/b26cccd87dcddc47b450a40f3b1ac3fe346efcff" }, { "url": "https://git.kernel.org/stable/c/e587af2c89ecc6382c518febea52fa9ba81e47c0" }, { "url": "https://git.kernel.org/stable/c/38c0abad45b190a30d8284a37264d2127a6ec303" } ], "title": "can: etas_es58x: populate ndo_change_mtu() to prevent buffer overflow", "x_generator": { "engine": "bippy-1.2.0" } } } }