{"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"}}]}}