{"id":"CVE-2025-38262","state":"PUBLISHED","title":"tty: serial: uartlite: register uart driver in init","description":"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.","publishedAt":"2025-07-09T10:42:37.410Z","updatedAt":"2026-10-15T21:52:13.087Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"5015eed450005bab6e5cb6810f7a62eab0434fc4","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"9c905fdbba68a6d73d39a6b7de9b9f0d6c46df87","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"6db06aaea07bb7c8e33a425cf7b98bf29ee6056e","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"8e958d10dd0ce5ae674cce460db5c9ca3f25243b","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"685d29f2c5057b32c7b1b46f2a7d303b926c8f72","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"f5e4229d94792b40e750f30c92bcf7a3107c72ef","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"6bd697b5fc39fd24e2aa418c7b7d14469f550a93","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/uartlite.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.20","versionType":"semver"},{"version":"5.4.296","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.15.187","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.143","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.96","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.36","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.5","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/uartlite.c"]}],"references":["https://git.kernel.org/stable/c/5015eed450005bab6e5cb6810f7a62eab0434fc4","https://git.kernel.org/stable/c/9c905fdbba68a6d73d39a6b7de9b9f0d6c46df87","https://git.kernel.org/stable/c/6db06aaea07bb7c8e33a425cf7b98bf29ee6056e","https://git.kernel.org/stable/c/8e958d10dd0ce5ae674cce460db5c9ca3f25243b","https://git.kernel.org/stable/c/685d29f2c5057b32c7b1b46f2a7d303b926c8f72","https://git.kernel.org/stable/c/f5e4229d94792b40e750f30c92bcf7a3107c72ef","https://git.kernel.org/stable/c/6bd697b5fc39fd24e2aa418c7b7d14469f550a93","https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/38xxx/CVE-2025-38262.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-38262","state":"PUBLISHED","datePublished":"2025-07-09T10:42:37.410Z","dateUpdated":"2026-10-15T21:52:13.087Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T04:51:23.997Z"},"containers":{"cna":{"title":"tty: serial: uartlite: register uart driver in init","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"5015eed450005bab6e5cb6810f7a62eab0434fc4","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"9c905fdbba68a6d73d39a6b7de9b9f0d6c46df87","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"6db06aaea07bb7c8e33a425cf7b98bf29ee6056e","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"8e958d10dd0ce5ae674cce460db5c9ca3f25243b","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"685d29f2c5057b32c7b1b46f2a7d303b926c8f72","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"f5e4229d94792b40e750f30c92bcf7a3107c72ef","versionType":"git"},{"version":"238b8721a554a33a451a3f13bdb5be8fe5cfc927","status":"affected","lessThan":"6bd697b5fc39fd24e2aa418c7b7d14469f550a93","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/uartlite.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.20","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.20","versionType":"semver"},{"version":"5.4.296","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.15.187","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.143","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.96","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.36","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.5","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/uartlite.c"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:00:50.359Z"},"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"}]}]}],"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":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T17:36:04.315Z"}},{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2025-38262","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T21:49:09.978264Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T21:52:13.087Z"}}]}}}