{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-39873", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T07:20:57.144Z", "datePublished": "2025-09-23T06:00:46.157Z", "dateUpdated": "2026-08-05T12:05:49.898Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:05:49.898Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncan: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB\n\ncan_put_echo_skb() takes ownership of the SKB and it may be freed\nduring or after the call.\n\nHowever, xilinx_can xcan_write_frame() keeps using SKB after the call.\n\nFix that by only calling can_put_echo_skb() after the code is done\ntouching the SKB.\n\nThe tx_lock is held for the entire xcan_write_frame() execution and\nalso on the can_get_echo_skb() side so the order of operations does not\nmatter.\n\nAn earlier fix commit 3d3c817c3a40 (\"can: xilinx_can: Fix usage of skb\nmemory\") did not move the can_put_echo_skb() call far enough.\n\n[mkl: add \"commit\" in front of sha1 in patch description]\n[mkl: fix indention]" } ], "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 - The vulnerable code is only reached from `ndo_start_xmit` on the xilinx_can device, i.e. by a local process transmitting a frame through a `PF_CAN` socket (`sendmsg()`); received bus traffic does not enter this path. Exploitation therefore requires local system access.\nAC:L - The attacker drives both the transmission and the conditions that make `can_put_echo_skb()` free the SKB (TX flooding to saturate the FIFO/echo slots, memory pressure to fail the `GFP_ATOMIC` `skb_clone`), and can retry indefinitely at line rate; the free is not a race the attacker cannot influence.\nPR:L - `can_create()` in net/can/af_can.c and the CAN_RAW protocol perform no capability check, so any unprivileged local user can open a raw CAN socket, bind it to the interface and transmit. No root or CAP_NET_ADMIN is needed to reach `xcan_write_frame()`.\nUI:N - The attacker's own `sendmsg()` call drives the whole path; no victim action or cooperation is required.\nS:U - The corruption stays within the kernel's own security authority — freed kernel heap and the driver's MMIO window — with no crossing of a hypervisor, IOMMU or sandbox boundary.\nC:H - The UAF reads freed (and, with a groomed `cf->len`, out-of-bounds) kernel heap contents and writes them into the CAN controller's TX registers, which are then transmitted on the physical CAN bus where any node — including the attacker's — can read them, giving direct kernel memory disclosure.\nI:H - `cf->len` read from reclaimed memory is unbounded (up to 255), so the write loop overruns the mailbox's data window and writes attacker-influenced dwords into adjacent CAN controller registers, and a UAF of this kind is generally leverageable into heap-spray-based write primitives; it also injects arbitrary frame content onto a safety-critical bus.\nA:H - The use-after-free triggers a KASAN panic on hardened kernels, and the out-of-bounds register writes plus lost echo-SKB accounting corrupt controller state and permanently wedge the TX queue (`netif_stop_queue()` with no matching completion), producing a crash or denial of CAN service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/can/xilinx_can.c" ], "versions": [ { "version": "1598efe57b3e768056e4ca56cb9cf33111e68d1c", "lessThan": "e202ffd9e54538ef67ec301ebd6d9da4823466c9", "status": "affected", "versionType": "git" }, { "version": "1598efe57b3e768056e4ca56cb9cf33111e68d1c", "lessThan": "1139321161a3ba5e45e61e0738b37f42f20bc57a", "status": "affected", "versionType": "git" }, { "version": "1598efe57b3e768056e4ca56cb9cf33111e68d1c", "lessThan": "94b050726288a56a6b8ff55aa641f2fedbd3b44c", "status": "affected", "versionType": "git" }, { "version": "1598efe57b3e768056e4ca56cb9cf33111e68d1c", "lessThan": "725b33deebd6e4c96fe7893f384510a54258f28f", "status": "affected", "versionType": "git" }, { "version": "1598efe57b3e768056e4ca56cb9cf33111e68d1c", "lessThan": "668cc1e3bb21101d074e430de1b7ba8fd10189e7", "status": "affected", "versionType": "git" }, { "version": "1598efe57b3e768056e4ca56cb9cf33111e68d1c", "lessThan": "ef79f00be72bd81d2e1e6f060d83cf7e425deee4", "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/xilinx_can.c" ], "versions": [ { "version": "4.19", "status": "affected" }, { "version": "0", "lessThan": "4.19", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.194", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.153", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.107", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.48", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16.8", "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": "4.19", "versionEndExcluding": "5.15.194" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "6.1.153" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "6.6.107" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "6.12.48" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "6.16.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19", "versionEndExcluding": "6.17" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e202ffd9e54538ef67ec301ebd6d9da4823466c9" }, { "url": "https://git.kernel.org/stable/c/1139321161a3ba5e45e61e0738b37f42f20bc57a" }, { "url": "https://git.kernel.org/stable/c/94b050726288a56a6b8ff55aa641f2fedbd3b44c" }, { "url": "https://git.kernel.org/stable/c/725b33deebd6e4c96fe7893f384510a54258f28f" }, { "url": "https://git.kernel.org/stable/c/668cc1e3bb21101d074e430de1b7ba8fd10189e7" }, { "url": "https://git.kernel.org/stable/c/ef79f00be72bd81d2e1e6f060d83cf7e425deee4" } ], "title": "can: xilinx_can: xcan_write_frame(): fix use-after-free of transmitted SKB", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T17:44:20.103Z" } } ] } }