{"id":"CVE-2025-38040","title":"serial: mctrl_gpio: split disable_ms into sync and no_sync APIs","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nserial: mctrl_gpio: split disable_ms into sync and no_sync APIs\n\nThe following splat has been observed on a SAMA5D27 platform using\natmel_serial:\n\nBUG: sleeping functio…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < 68435c1fa3db696db4f480385db9e50e26691d0d","Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < c504c11b94d6e4ad818ca5578dffa8ff29ad0f20","Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < e6a46719a2369eb5186d4f7e6c0478720ca1ec3d","Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < 7187ec6b0b9ff22ebac2c3bb4178b7dbbdc0a55a","Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < 1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685","Linux 4.4"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T20:48:34.069369Z"},"published":"2025-06-18","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:52:13.449Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2025-38040","references":[{"url":"https://git.kernel.org/stable/c/68435c1fa3db696db4f480385db9e50e26691d0d"},{"url":"https://git.kernel.org/stable/c/c504c11b94d6e4ad818ca5578dffa8ff29ad0f20"},{"url":"https://git.kernel.org/stable/c/e6a46719a2369eb5186d4f7e6c0478720ca1ec3d"},{"url":"https://git.kernel.org/stable/c/7187ec6b0b9ff22ebac2c3bb4178b7dbbdc0a55a"},{"url":"https://git.kernel.org/stable/c/1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685"}],"tags":["cve.org"],"epss":0.00195,"epssPercentile":0.09289,"ingestedAt":"2026-11-05T22:38:31.912Z","slug":"CVE-2025-38040","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nserial: mctrl_gpio: split disable_ms into sync and no_sync APIs\n\nThe following splat has been observed on a SAMA5D27 platform using\natmel_serial:\n\nBUG: sleeping function called from invalid context at kernel/irq/manage.c:738\nin_atomic(): 1, irqs_disabled(): 128, non_block: 0, pid: 27, name: kworker/u5:0\npreempt_count: 1, expected: 0\nINFO: lockdep is turned off.\nirq event stamp: 0\nhardirqs last  enabled at (0): [<00000000>] 0x0\nhardirqs last disabled at (0): [<c01588f0>] copy_process+0x1c4c/0x7bec\nsoftirqs last  enabled at (0): [<c0158944>] copy_process+0x1ca0/0x7bec\nsoftirqs last disabled at (0): [<00000000>] 0x0\nCPU: 0 UID: 0 PID: 27 Comm: kworker/u5:0 Not tainted 6.13.0-rc7+ #74\nHardware name: Atmel SAMA5\nWorkqueue: hci0 hci_power_on [bluetooth]\nCall trace:\n  unwind_backtrace from show_stack+0x18/0x1c\n  show_stack from dump_stack_lvl+0x44/0x70\n  dump_stack_lvl from __might_resched+0x38c/0x598\n  __might_resched from disable_irq+0x1c/0x48\n  disable_irq from mctrl_gpio_disable_ms+0x74/0xc0\n  mctrl_gpio_disable_ms from atmel_disable_ms.part.0+0x80/0x1f4\n  atmel_disable_ms.part.0 from atmel_set_termios+0x764/0x11e8\n  atmel_set_termios from uart_change_line_settings+0x15c/0x994\n  uart_change_line_settings from uart_set_termios+0x2b0/0x668\n  uart_set_termios from tty_set_termios+0x600/0x8ec\n  tty_set_termios from ttyport_set_flow_control+0x188/0x1e0\n  ttyport_set_flow_control from wilc_setup+0xd0/0x524 [hci_wilc]\n  wilc_setup [hci_wilc] from hci_dev_open_sync+0x330/0x203c [bluetooth]\n  hci_dev_open_sync [bluetooth] from hci_dev_do_open+0x40/0xb0 [bluetooth]\n  hci_dev_do_open [bluetooth] from hci_power_on+0x12c/0x664 [bluetooth]\n  hci_power_on [bluetooth] from process_one_work+0x998/0x1a38\n  process_one_work from worker_thread+0x6e0/0xfb4\n  worker_thread from kthread+0x3d4/0x484\n  kthread from ret_from_fork+0x14/0x28\n\nThis warning is emitted when trying to toggle, at the highest level,\nsome flow control (with serdev_device_set_flow_control) in a device\ndriver. At the lowest level, the atmel_serial driver is using\nserial_mctrl_gpio lib to enable/disable the corresponding IRQs\naccordingly.  The warning emitted by CONFIG_DEBUG_ATOMIC_SLEEP is due to\ndisable_irq (called in mctrl_gpio_disable_ms) being possibly called in\nsome atomic context (some tty drivers perform modem lines configuration\nin regions protected by port lock).\n\nSplit mctrl_gpio_disable_ms into two differents APIs, a non-blocking one\nand a blocking one. Replace mctrl_gpio_disable_ms calls with the\nrelevant version depending on whether the call is protected by some port\nlock.\n\n## Affected\n\n- `Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < 68435c1fa3db696db4f480385db9e50e26691d0d`\n- `Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < c504c11b94d6e4ad818ca5578dffa8ff29ad0f20`\n- `Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < e6a46719a2369eb5186d4f7e6c0478720ca1ec3d`\n- `Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < 7187ec6b0b9ff22ebac2c3bb4178b7dbbdc0a55a`\n- `Linux >= ce59e48fdbad2aa6609ceb87e1306ec69e577e05 < 1bd2aad57da95f7f2d2bb52f7ad15c0f4993a685`\n- `Linux 4.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}