{"id":"CVE-2026-74652","state":"PUBLISHED","title":"serial: amba-pl011: cancel RS485 hrtimers after freeing IRQ","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: amba-pl011: cancel RS485 hrtimers after freeing IRQ\n\nThe RS485 trigger hrtimers are embedded in the devm-managed port and can\nfire after it is freed. The IRQ handler can arm a timer, so free the IRQ\nfirst and then cancel both timers.\n\nComplete the RS485 stop without arming a timer, and cancel the timers\nin remove() for the suspend-then-unbind path, where shutdown is not\ncalled.\n\nThis issue was found by an in-house static analysis tool.","publishedAt":"2026-08-22T15:32:27.799Z","updatedAt":"2026-08-25T05:41:10.525Z","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":"2c1fd53af21b8cb13878b054894d33d3383eb1f3","status":"affected","lessThan":"759ead98a39fb625be302f9aa66290985dcaa325","versionType":"git"},{"version":"2c1fd53af21b8cb13878b054894d33d3383eb1f3","status":"affected","lessThan":"e57f0aa5c35be37218ba0e4887b241584dd4b2d2","versionType":"git"},{"version":"2c1fd53af21b8cb13878b054894d33d3383eb1f3","status":"affected","lessThan":"36672c8d7d14e9c43287528455d2c97b526ea6ad","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/amba-pl011.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.45","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","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/amba-pl011.c"]}],"references":["https://git.kernel.org/stable/c/759ead98a39fb625be302f9aa66290985dcaa325","https://git.kernel.org/stable/c/e57f0aa5c35be37218ba0e4887b241584dd4b2d2","https://git.kernel.org/stable/c/36672c8d7d14e9c43287528455d2c97b526ea6ad"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/74xxx/CVE-2026-74652.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-74652","state":"PUBLISHED","datePublished":"2026-08-22T15:32:27.799Z","dateUpdated":"2026-08-25T05:41:10.525Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-15T05:44:03.923Z"},"containers":{"cna":{"title":"serial: amba-pl011: cancel RS485 hrtimers after freeing IRQ","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: amba-pl011: cancel RS485 hrtimers after freeing IRQ\n\nThe RS485 trigger hrtimers are embedded in the devm-managed port and can\nfire after it is freed. The IRQ handler can arm a timer, so free the IRQ\nfirst and then cancel both timers.\n\nComplete the RS485 stop without arming a timer, and cancel the timers\nin remove() for the suspend-then-unbind path, where shutdown is not\ncalled.\n\nThis issue was found by an in-house static analysis tool."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2c1fd53af21b8cb13878b054894d33d3383eb1f3","status":"affected","lessThan":"759ead98a39fb625be302f9aa66290985dcaa325","versionType":"git"},{"version":"2c1fd53af21b8cb13878b054894d33d3383eb1f3","status":"affected","lessThan":"e57f0aa5c35be37218ba0e4887b241584dd4b2d2","versionType":"git"},{"version":"2c1fd53af21b8cb13878b054894d33d3383eb1f3","status":"affected","lessThan":"36672c8d7d14e9c43287528455d2c97b526ea6ad","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/tty/serial/amba-pl011.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.14","versionType":"semver"},{"version":"6.18.45","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.9","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","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/amba-pl011.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/759ead98a39fb625be302f9aa66290985dcaa325"},{"url":"https://git.kernel.org/stable/c/e57f0aa5c35be37218ba0e4887b241584dd4b2d2"},{"url":"https://git.kernel.org/stable/c/36672c8d7d14e9c43287528455d2c97b526ea6ad"}],"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 bug is in the PL011 UART/RS485 driver and is reached only via local tty access (open/ioctl TIOCSRS485, write, close) on /dev/ttyAMA* or similar nodes; it is not reachable from the network or from RS485 bus traffic alone without local device control.\nAC:L - An attacker with tty access can enable RS485, queue TX with RTS delay timers, and close or race teardown to arm hrtimers during shutdown/remove; they control both the TX state machine and teardown timing, making the race reliably triggerable.\nPR:L - Exploitation requires write access to the UART tty device (typically dialout group membership), not root; ioctl/write/close drive the RS485 timers and buggy shutdown path, while the suspend-then-unbind heap UAF needs admin but is not the minimum privilege bar.\nUI:N - No victim interaction is required; the attacker who holds the tty fd performs TIOCSRS485, transmission, and port close or coordinates teardown themselves without needing another user to act.\nS:U - Impact is confined to kernel memory and hardware on the same host (crash, corruption, potential privilege escalation); it does not cross VM, container, or IOMMU security boundaries.\nC:H - RS485 hrtimers embedded in the devm uart_amba_port can fire after the port is freed during remove or buggy shutdown, causing a use-after-free that exposes freed kernel heap contents and enables arbitrary memory read primitives.\nI:H - UAF timer callbacks (pl011_trigger_start_tx/pl011_trigger_stop_tx) continue operating on freed uart_amba_port memory, performing MMIO reads/writes and state updates that enable heap grooming and kernel data corruption or control-flow hijacking.\nA:H - Use-after-free and concurrent hrtimer callbacks during/after port teardown can cause kernel oops, panic, or hang; RS485 timers may also fire on a partially shut down UART, destabilizing the system."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-25T05:41:10.525Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.18.45"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.1.9"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}