{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53094", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-05-02T15:51:43.552Z", "datePublished": "2025-05-02T15:55:39.045Z", "dateUpdated": "2026-08-05T09:12:45.604Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:12:45.604Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntty: serial: fsl_lpuart: fix race on RX DMA shutdown\n\nFrom time to time DMA completion can come in the middle of DMA shutdown:\n\n:\t\t\t\t:\nlpuart32_shutdown()\n lpuart_dma_shutdown()\n del_timer_sync()\n\t\t\t\t\tlpuart_dma_rx_complete()\n\t\t\t\t\t lpuart_copy_rx_to_tty()\n\t\t\t\t\t mod_timer()\n lpuart_dma_rx_free()\n\nWhen the timer fires a bit later, sport->dma_rx_desc is NULL:\n\nUnable to handle kernel NULL pointer dereference at virtual address 0000000000000004\npc : lpuart_copy_rx_to_tty+0xcc/0x5bc\nlr : lpuart_timer_func+0x1c/0x2c\nCall trace:\n lpuart_copy_rx_to_tty\n lpuart_timer_func\n call_timer_fn\n __run_timers.part.0\n run_timer_softirq\n __do_softirq\n __irq_exit_rcu\n irq_exit\n handle_domain_irq\n gic_handle_irq\n call_on_irq_stack\n do_interrupt_handler\n ...\n\nTo fix this fold del_timer_sync() into lpuart_dma_rx_free() after\ndmaengine_terminate_sync() to make sure timer will not be re-started in\nlpuart_copy_rx_to_tty() <= lpuart_dma_rx_complete()." } ], "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 RX DMA shutdown path is reached via local tty operations (close → uart_shutdown, or tcsetattr → set_termios) on the fsl_lpuart device node (/dev/ttyLP*), not via network packets or a required physical plug-in attack.\nAC:L - An attacker who can open the LPUART tty controls the shutdown/set_termios side and can generate continuous UART RX (serial peer, Bluetooth HCI-over-UART traffic, or similar) to drive DMA completion IRQs, so both sides of the race are attacker-influenced and retryable.\nPR:L - Exploitation requires opening the serial tty device as an unprivileged local user with ordinary device permissions (e.g. dialout/tty group), not real root or init-namespace admin capabilities.\nUI:N - The attacker triggers the race themselves by opening the port and closing it or changing termios while RX DMA is active; no separate victim action is required.\nS:U - Impact stays within the kernel/host security authority (crash or memory corruption in the serial driver); this is not a VM escape, IOMMU bypass, or other cross-boundary breakout.\nC:H - After del_timer_sync, a DMA completion can re-arm the timer before lpuart_dma_rx_free finishes; the timer may run after kfree(rx_ring.buf) while dma_rx_desc is still non-NULL, so lpuart_copy_rx_to_tty can read freed DMA buffer contents into the tty flip buffer (UAF disclosure), especially on the set_termios path where the fd stays open.\nI:H - The same race yields use-after-free / dangling use of the DMA descriptor and RX ring (async_tx_ack writes through dma_rx_desc after terminate_sync may have recycled it, plus use of freed buffer state), which is memory corruption exploitable beyond a clean crash.\nA:H - The commonly observed outcome is a kernel NULL pointer dereference in lpuart_copy_rx_to_tty from lpuart_timer_func (oops/panic), and the UAF paths similarly cause reliable kernel crashes." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/tty/serial/fsl_lpuart.c" ], "versions": [ { "version": "4a8588a1cf867333187d9ff071e6fbdab587d194", "lessThan": "19a98d56dfedafb25652bdb9cd48a4e73ceba702", "status": "affected", "versionType": "git" }, { "version": "4a8588a1cf867333187d9ff071e6fbdab587d194", "lessThan": "90530e7214c8a04dcdde57502d93fa96af288c38", "status": "affected", "versionType": "git" }, { "version": "4a8588a1cf867333187d9ff071e6fbdab587d194", "lessThan": "954fc9931f0aabf272b5674cf468affdd88d3a36", "status": "affected", "versionType": "git" }, { "version": "4a8588a1cf867333187d9ff071e6fbdab587d194", "lessThan": "2a36b444cace9580380467fd1183bb5e85bcc80a", "status": "affected", "versionType": "git" }, { "version": "4a8588a1cf867333187d9ff071e6fbdab587d194", "lessThan": "1be6f2b15f902c02e055ae0b419ca789200473c9", "status": "affected", "versionType": "git" }, { "version": "5716a781032693d0f812ed06528d98195e9df028", "status": "affected", "versionType": "git" }, { "version": "0d5cb6e8b4b62d8efd1a470615894276341d6db9", "status": "affected", "versionType": "git" }, { "version": "3.18.9", "lessThan": "3.19", "status": "affected", "versionType": "semver" }, { "version": "3.19.1", "lessThan": "3.20", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/tty/serial/fsl_lpuart.c" ], "versions": [ { "version": "4.0", "status": "affected" }, { "version": "0", "lessThan": "4.0", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.177", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.105", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.23", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2.8", "lessThanOrEqual": "6.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.3", "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": "4.0", "versionEndExcluding": "5.10.177" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "5.15.105" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "6.1.23" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "6.2.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.0", "versionEndExcluding": "6.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.18.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.19.1" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/19a98d56dfedafb25652bdb9cd48a4e73ceba702" }, { "url": "https://git.kernel.org/stable/c/90530e7214c8a04dcdde57502d93fa96af288c38" }, { "url": "https://git.kernel.org/stable/c/954fc9931f0aabf272b5674cf468affdd88d3a36" }, { "url": "https://git.kernel.org/stable/c/2a36b444cace9580380467fd1183bb5e85bcc80a" }, { "url": "https://git.kernel.org/stable/c/1be6f2b15f902c02e055ae0b419ca789200473c9" } ], "title": "tty: serial: fsl_lpuart: fix race on RX DMA shutdown", "x_generator": { "engine": "bippy-1.2.0" } } } }