From 4aab0ca0a0f7760e33edcb4e47576064d05128f5 Mon Sep 17 00:00:00 2001 From: Cheng-Yu Lee Date: Fri, 9 Jan 2026 11:26:33 +0800 Subject: [PATCH] regmap: Fix race condition in hwspinlock irqsave routine [ Upstream commit 4b58aac989c1e3fafb1c68a733811859df388250 ] Previously, the address of the shared member '&map->spinlock_flags' was passed directly to 'hwspin_lock_timeout_irqsave'. This creates a race condition where multiple contexts contending for the lock could overwrite the shared flags variable, potentially corrupting the state for the current lock owner. Fix this by using a local stack variable 'flags' to store the IRQ state temporarily. Fixes: 8698b9364710 ("regmap: Add hardware spinlock support") Signed-off-by: Cheng-Yu Lee Co-developed-by: Yu-Chun Lin Signed-off-by: Yu-Chun Lin Link: https://patch.msgid.link/20260109032633.8732-1-eleanor.lin@realtek.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/base/regmap/regmap.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 66b3840bd96e..70cde1bd0400 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -408,9 +408,11 @@ static void regmap_lock_hwlock_irq(void *__map) static void regmap_lock_hwlock_irqsave(void *__map) { struct regmap *map = __map; + unsigned long flags = 0; hwspin_lock_timeout_irqsave(map->hwlock, UINT_MAX, - &map->spinlock_flags); + &flags); + map->spinlock_flags = flags; } static void regmap_unlock_hwlock(void *__map)