{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38262", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.997Z", "datePublished": "2025-07-09T10:42:37.410Z", "dateUpdated": "2026-08-05T12:00:50.359Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:00:50.359Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: serial: uartlite: register uart driver in init\n\nWhen two instances of uart devices are probing, a concurrency race can\noccur. If one thread calls uart_register_driver function, which first\nallocates and assigns memory to 'uart_state' member of uart_driver\nstructure, the other instance can bypass uart driver registration and\ncall ulite_assign. This calls uart_add_one_port, which expects the uart\ndriver to be fully initialized. This leads to a kernel panic due to a\nnull pointer dereference:\n\n[ 8.143581] BUG: kernel NULL pointer dereference, address: 00000000000002b8\n[ 8.156982] #PF: supervisor write access in kernel mode\n[ 8.156984] #PF: error_code(0x0002) - not-present page\n[ 8.156986] PGD 0 P4D 0\n...\n[ 8.180668] RIP: 0010:mutex_lock+0x19/0x30\n[ 8.188624] Call Trace:\n[ 8.188629] ? __die_body.cold+0x1a/0x1f\n[ 8.195260] ? page_fault_oops+0x15c/0x290\n[ 8.209183] ? __irq_resolve_mapping+0x47/0x80\n[ 8.209187] ? exc_page_fault+0x64/0x140\n[ 8.209190] ? asm_exc_page_fault+0x22/0x30\n[ 8.209196] ? mutex_lock+0x19/0x30\n[ 8.223116] uart_add_one_port+0x60/0x440\n[ 8.223122] ? proc_tty_register_driver+0x43/0x50\n[ 8.223126] ? tty_register_driver+0x1ca/0x1e0\n[ 8.246250] ulite_probe+0x357/0x4b0 [uartlite]\n\nTo prevent it, move uart driver registration in to init function. This\nwill ensure that uart_driver is always registered when probe function\nis called." } ], "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 window lives entirely in the uartlite platform-driver probe path, reachable only from local device/module instantiation (module load, deferred-probe worker, DT-overlay/FPGA-region or sysfs bind) on the affected host. No remote, adjacent, or physical-interface data reaches this code — the race is in driver registration, not in serial data handling.\nAC:L - Success requires the system to be in a specific state the attacker cannot create or influence — two uartlite instances probing simultaneously with one thread inside the few-microsecond window between `drv->state = kzalloc()` and `tty_port_init()`/`tty_register_driver()`. There is no way to widen, stall, or re-trigger that window from a local attacker's position, so it is a condition truly beyond attacker control.\nPR:L - Scored as a local unprivileged attacker present on an affected FPGA/embedded system when the concurrent probe occurs; the code itself performs no capability check. Deliberately forcing a probe (modprobe, sysfs bind, DT overlay) would need root, but the higher-severity assumption of a merely unprivileged local presence is used here.\nUI:N - The race fires during driver/device initialization driven by the kernel's own probe machinery; no victim action such as opening a device, mounting a filesystem, or loading a file is required.\nS:U - The corruption is confined to kernel data structures (`uart_driver.state`, `tty_port`, slab objects) within the same security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - This is not a bare NULL dereference — `uart_add_one_port()` reads through a half-built or already-`kfree()`d `drv->state`/`drv->tty_driver` (`drv->tty_driver->minor_start`, `state->uart_port`), giving reads of freed slab memory whose contents can be reallocated to other objects, so it is leverageable for kernel memory disclosure.\nI:H - In the double-registration interleaving the losing thread's error path `kfree()`s the shared `drv->state` array while the winner writes through it (`atomic_set(&state->refcount,1)`, `init_waitqueue_head()`, `state->uart_port = uport`, `tty_port_link_device()`), a use-after-free write that plants kernel pointers and performs list/mutex operations inside a freed, potentially reallocated slab object — memory corruption usable for control-flow hijacking.\nA:H - The documented and reproduced outcome is an immediate kernel panic (`BUG: kernel NULL pointer dereference` in `mutex_lock` from `uart_add_one_port`), and `BUG_ON(drv->state)` in the concurrent `uart_register_driver()` is a second crash path. On 5.4–6.12 the oops happens while the global `port_mutex` is held, permanently deadlocking all further serial-port and console registration even if the box survives the oops." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/tty/serial/uartlite.c" ], "versions": [ { "version": "238b8721a554a33a451a3f13bdb5be8fe5cfc927", "lessThan": "5015eed450005bab6e5cb6810f7a62eab0434fc4", "status": "affected", "versionType": "git" }, { "version": "238b8721a554a33a451a3f13bdb5be8fe5cfc927", "lessThan": "9c905fdbba68a6d73d39a6b7de9b9f0d6c46df87", "status": "affected", "versionType": "git" }, { "version": "238b8721a554a33a451a3f13bdb5be8fe5cfc927", "lessThan": "6db06aaea07bb7c8e33a425cf7b98bf29ee6056e", "status": "affected", "versionType": "git" }, { "version": "238b8721a554a33a451a3f13bdb5be8fe5cfc927", "lessThan": "8e958d10dd0ce5ae674cce460db5c9ca3f25243b", "status": "affected", "versionType": "git" }, { "version": "238b8721a554a33a451a3f13bdb5be8fe5cfc927", "lessThan": "685d29f2c5057b32c7b1b46f2a7d303b926c8f72", "status": "affected", "versionType": "git" }, { "version": "238b8721a554a33a451a3f13bdb5be8fe5cfc927", "lessThan": "f5e4229d94792b40e750f30c92bcf7a3107c72ef", "status": "affected", "versionType": "git" }, { "version": "238b8721a554a33a451a3f13bdb5be8fe5cfc927", "lessThan": "6bd697b5fc39fd24e2aa418c7b7d14469f550a93", "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/tty/serial/uartlite.c" ], "versions": [ { "version": "2.6.20", "status": "affected" }, { "version": "0", "lessThan": "2.6.20", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.296", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.187", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.143", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.96", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.36", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.5", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "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": "2.6.20", "versionEndExcluding": "5.4.296" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.20", "versionEndExcluding": "5.15.187" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.20", "versionEndExcluding": "6.1.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.20", "versionEndExcluding": "6.6.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.20", "versionEndExcluding": "6.12.36" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.20", "versionEndExcluding": "6.15.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.20", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5015eed450005bab6e5cb6810f7a62eab0434fc4" }, { "url": "https://git.kernel.org/stable/c/9c905fdbba68a6d73d39a6b7de9b9f0d6c46df87" }, { "url": "https://git.kernel.org/stable/c/6db06aaea07bb7c8e33a425cf7b98bf29ee6056e" }, { "url": "https://git.kernel.org/stable/c/8e958d10dd0ce5ae674cce460db5c9ca3f25243b" }, { "url": "https://git.kernel.org/stable/c/685d29f2c5057b32c7b1b46f2a7d303b926c8f72" }, { "url": "https://git.kernel.org/stable/c/f5e4229d94792b40e750f30c92bcf7a3107c72ef" }, { "url": "https://git.kernel.org/stable/c/6bd697b5fc39fd24e2aa418c7b7d14469f550a93" } ], "title": "tty: serial: uartlite: register uart driver in init", "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": "2025-11-03T17:36:04.315Z" } } ] } }