Unverified Commit 4b58aac9 authored by Cheng-Yu Lee's avatar Cheng-Yu Lee Committed by Mark Brown
Browse files

regmap: Fix race condition in hwspinlock irqsave routine 



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: 8698b936 ("regmap: Add hardware spinlock support")
Signed-off-by: default avatarCheng-Yu Lee <cylee12@realtek.com>
Co-developed-by: default avatarYu-Chun Lin <eleanor.lin@realtek.com>
Signed-off-by: default avatarYu-Chun Lin <eleanor.lin@realtek.com>
Link: https://patch.msgid.link/20260109032633.8732-1-eleanor.lin@realtek.com


Signed-off-by: default avatarMark Brown <broonie@kernel.org>
parent f3f380ce

drivers/base/regmap/regmap.c

+3 −1
Original line number Diff line number Diff line
@@ -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)