kernel/linux.git/drivers/watchdog, branch v6.18.48

watchdog: at91sam9_wdt: prevent timer rearm during teardown

2026-08-19T16:17:44+00:00

[ Upstream commit 8444d66aa6b6e7fe0a26fa1a00a11cb4d0523783 ] at91_ping() rearms the watchdog timer from its callback. timer_delete() neither waits for a running callback nor prevents it from rearming the timer, so probe failure or driver removal can leave the timer accessing the devm-allocated at91wdt after it has been freed. Use timer_shutdown_sync() on both teardown paths. It waits for a running callback and rejects any attempt by the callback to rearm the timer. Fixes: 5161b31dc39a ("watchdog: at91sam9_wdt: better watchdog support") Signed-off-by: Hongyan Xu Link: https://lore.kernel.org/r/20260806060613.1830-1-getshell@seu.edu.cn Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: bd96801_wdt: Fix timeout for enabled WDG

2026-08-19T16:17:20+00:00

[ Upstream commit 1246aa2b6ccc8944676bd24ff3e37cc56b93b51b ] When watchdog is enabled at the probe time, the bd96801 driver retrieves the timeout configuration from the registers to set-up the heart-beat values. As Sashiko pointed out at https://lore.kernel.org/all/20260722085819.495211F000E9@smtp.kernel.org/ the timeout values are incorrectly computed in driver, resulting wrong heartbeat. This leads to devere problems if watchdog was enabled at probe time. According to the data-sheet, the "too fast" ping limit is configured as multiple of FASTNG_MIN. Furthermore, the "too slow" ping limit is configured as multiples of "too fast" timeout. The FASTNG_MIN is set to 11, meaning 1.1 mS and "too fast" and "too slow" limits are computed from this. Hence, converting the limits to mS should be done by dividing by 10, not by dividing by USEC_PER_MSEC. Fix this by dividing the timeout values with correct scaling factor. While at it, fix whitespace problem (double empty line). Signed-off-by: Matti Vaittinen Fixes: 09dad69757b6 ("watchdog: ROHM BD96801 PMIC WDG driver") Link: https://lore.kernel.org/r/amxskHmQbi9v-8_l@mva-rohm [groeck: Added reference to whitespace change to description] Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: s32g_wdt: remove incorrect options in watchdog_info struct

2026-08-03T09:22:05+00:00

commit 2b37415618bfc6a83d4aceb00fd8d6491096f2ed upstream. The s32g_wdt driver uses two incorrect constants in the options field of its watchdog_info struct. This bit mask should contain WDIOF_* constants, but the driver uses two WDIOC_* ioctl constants (in addition to correct WDIOF_* constants). This causes many incorrect bits to be set in the bit mask. The functionality indicated by these ioctl constants is supported by all drivers using the watchdog framework, so this patch simply removes them. Fixes: bd3f54ec559b ("watchdog: Add the Watchdog Timer for the NXP S32 platform") Cc: stable@vger.kernel.org # 6.18+ Signed-off-by: Ethan Nelson-Moore Acked-by: Daniel Lezcano Link: https://lore.kernel.org/r/20260505024409.60301-1-enelsonmoore@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman

watchdog: airoha: Prevent division by zero when clock frequency is zero

2026-08-03T09:21:37+00:00

[ Upstream commit bcfcd7619f277842430d197556463b401b839ee9 ] clk_get_rate() can return 0 when the clock provider is not properly configured or the clock is unmanaged. The driver uses wdt_freq as a divisor directly in airoha_wdt_probe() to compute max_timeout and in airoha_wdt_get_timeleft() to compute the remaining time, which results in a division by zero. Add a check for wdt_freq == 0 in probe and return -EINVAL with dev_err_probe() to prevent the division by zero and provide a diagnostic message. Fixes: 3cf67f3769b8 ("watchdog: Add support for Airoha EN7851 watchdog") Signed-off-by: Wayen Yan Link: https://lore.kernel.org/r/178347932594.81327.4834644880399144119@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: pretimeout: Fix UAF in watchdog_unregister_governor()

2026-08-03T09:21:37+00:00

[ Upstream commit 7362ba0f9c96ac3ad6a2ca3995bd9fc9a28a8661 ] When a watchdog governor is unregistered, it updates existing watchdog devices that were using this governor by falling back to `default_gov`. If the governor being unregistered is currently set as `default_gov`, the `default_gov` is never cleared. This leads to 2 use-after-free issues: 1. New watchdog devices registered after this point will inherit the dangling `default_gov`. 2. Existing watchdog devices using the unregistered governor will have their `wdd->gov` reassigned to the dangling `default_gov`. Fix the UAF by clearing `default_gov` if it matches the governor being unregistered. Fixes: da0d12ff2b82 ("watchdog: pretimeout: add panic pretimeout governor") Signed-off-by: Tzung-Bi Shih Link: https://lore.kernel.org/r/20260707101803.3598173-1-tzungbi@kernel.org Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: unregister PM notifier on watchdog unregister

2026-07-24T14:16:04+00:00

[ Upstream commit a298c7302ee9584a7a1ac1e8acbede8d98ab51a4 ] watchdog_register_device() registers wdd->pm_nb when WDOG_NO_PING_ON_SUSPEND is set, but watchdog_unregister_device() does not remove it. This leaves an embedded notifier block on the PM notifier chain after the watchdog device has been unregistered. A later suspend/resume notification can then call watchdog_pm_notifier() with a stale watchdog_device pointer, or at minimum after wdd->wd_data has been cleared by watchdog_dev_unregister(). Unregister the PM notifier before tearing down the watchdog device. Fixes: 60bcd91aafd2 ("watchdog: introduce watchdog_dev_suspend/resume") Signed-off-by: Yuho Choi Link: https://lore.kernel.org/r/20260601192005.1970805-1-dbgh9129@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: sprd_wdt: Remove redundant sprd_wdt_disable() on register failure

2026-07-24T14:15:45+00:00

[ Upstream commit 96b3cfc3b8ad0524d12fed1e08bc5df3ff345f64 ] The driver uses devm_add_action_or_reset() to register sprd_wdt_disable() as a managed cleanup action. When devm_watchdog_register_device() fails, the devm core will invoke the cleanup action automatically. The explicit sprd_wdt_disable() call in the error path is therefore redundant and results in adouble cleanup. Fixes: 78d9bfad2e89 ("watchdog: sprd_wdt: Convert to use device managed functions and other improvements") Signed-off-by: Felix Gu Reviewed-by: Guenter Roeck Reviewed-by: Baolin Wang Link: https://lore.kernel.org/r/20260223-sprd_wdt-v1-1-2e71f9a76ecb@gmail.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: sama5d4_wdt: Fix WDDIS detection on SAM9X60 and SAMA7G5

2026-07-24T14:15:45+00:00

[ Upstream commit e8bc610b14a99d24b0916635102cc52ba41def9b ] The driver hardcoded AT91_WDT_WDDIS (bit 15) in wdt_enabled and the probe initial state readout. SAM9X60 and SAMA7G5 use bit 12 (AT91_SAM9X60_WDDIS), causing incorrect WDDIS detection. Introduce a per-device wddis_mask field to select the correct WDDIS bit based on the compatible string. Fixes: 266da53c35fc ("watchdog: sama5d4: readout initial state") Co-developed-by: Andrei Simion Signed-off-by: Andrei Simion Signed-off-by: Balakrishnan Sambath Reviewed-by: Alexandre Belloni Link: https://lore.kernel.org/r/20260302113310.133989-2-balakrishnan.s@microchip.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: sp5100_tco: Use EFCH MMIO for newer Hygon FCH

2026-07-24T14:15:45+00:00

[ Upstream commit 4f675f036cd5e9cfbe6df5f24f8338158af96a4b ] Commit 009637de1f65 ("watchdog: sp5100_tco: support Hygon FCH/SCH (Server Controller Hub)") added Hygon vendor matching to the efch layout selection, but newer Hygon 0x790b SMBus devices still need the efch_mmio path. The efch_mmio path enables EFCH_PM_DECODEEN_WDT_TMREN before probing the watchdog MMIO block. If firmware leaves that bit clear and the driver picks the legacy efch path instead, probe falls back to the alternate window and fails with "Watchdog hardware is disabled". Select efch_mmio for Hygon 0x790b devices with revision 0x51 or later, matching the equivalent AMD behavior and allowing the watchdog to initialize on those systems. Fixes: 009637de1f65 ("watchdog: sp5100_tco: support Hygon FCH/SCH (Server Controller Hub)") Signed-off-by: Yingjie Gao Reviewed-by: Guenter Roeck Link: https://lore.kernel.org/r/20260402071617.634563-2-gaoyingjie@uniontech.com Signed-off-by: Guenter Roeck Signed-off-by: Sasha Levin

watchdog: apple: Add "apple,t8103-wdt" compatible

2026-07-18T14:53:30+00:00

commit 14ca4868886f2188401fe06cd7bf01a330b3fb99 upstream. After discussion with the devicetree maintainers we agreed to not extend lists with the generic compatible "apple,wdt" anymore [1]. Use "apple,t8103-wdt" as base compatible as it is the SoC the driver and bindings were written for. [1]: https://lore.kernel.org/asahi/12ab93b7-1fc2-4ce0-926e-c8141cfe81bf@kernel.org/ Fixes: 4ed224aeaf66 ("watchdog: Add Apple SoC watchdog driver") Cc: stable@vger.kernel.org Reviewed-by: Neal Gompa Signed-off-by: Janne Grunau Link: https://lore.kernel.org/r/20251231-watchdog-apple-t8103-base-compat-v1-1-1702a02e0c45@jannau.net Signed-off-by: Guenter Roeck Signed-off-by: Greg Kroah-Hartman