From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 2D37B39B94E for ; Sat, 28 Feb 2026 18:15:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302519; cv=none; b=XTrYvmry+kcSSajrmU9m+4a2YU19R/DeoP3Igrffc3OvmTrs1alhhUq984WuNVIEsIkfG5+kS+YdiUfj7QNJJbXTnN0swrYPh1wXJ74FAg8RZPKyaYF4ikFSE0U9zONWtclrnK81qhdVQqLHGBgFo2dzJLChj5IYt/HJtxmYZlY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302519; c=relaxed/simple; bh=g4+NciHAAqUsm5uOMgQsoAoJb/Jeg6lajn7NlOjFZKc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=I5L0ksG1zdzaFphTcJ1i3aZs4Wo+sky2CArQ8FHkn02PfFLvU+oLWeVo2ex8iDv6BG6vA1X216T2RKYZoykU3JYysKGLBnLkUgq6SjAVnLo397Pe3ZddTMRJ3Iu2O3AO9BJfdWSK0qYGzCoby/rmivka4qFTE/HxK96qvBRp1JE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=jrcKIcDN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="jrcKIcDN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 91A79C116D0; Sat, 28 Feb 2026 18:15:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302519; bh=g4+NciHAAqUsm5uOMgQsoAoJb/Jeg6lajn7NlOjFZKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=jrcKIcDN5zphYHzwVCvZ5gSVYAIg17SjCashpCgnUZoFz0r1yfYON6QgnfH7gtT6P 2RUeLH/cX83kr8LqTZ/VX9Kb8bLhH7K14+SLVAlnG7HA/YBp1KOzDSraFrAc4QNCXW zM6fHdO6yP/tYb+Dt2VKQOc9+3vyQQ9qhj3M7HmksWNZgSwxYMDd9lrmHk8u8pyQOM ryarqynOuoo9eLziUCFr5JjJFnL0Kk2sYnggus0qdA8IGwxBKdqvBW7ivQhMyktwM0 BMnKevnPIWPhev3vZ0TTuVJwMt7UmR493UuwRNnSXzhog0nKshE/xN+4nhrAAbFbnP XHZ6oOzl2t40A== From: Sasha Levin To: patches@lists.linux.dev Cc: Gui-Dong Han , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 5.15 016/164] PM: sleep: wakeirq: harden dev_pm_clear_wake_irq() against races Date: Sat, 28 Feb 2026 13:12:35 -0500 Message-ID: <20260228181505.1600663-16-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228181505.1600663-1-sashal@kernel.org> References: <20260228181505.1600663-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit From: Gui-Dong Han [ Upstream commit 5c9ecd8e6437cd55a38ea4f1e1d19cee8e226cb8 ] dev_pm_clear_wake_irq() currently uses a dangerous pattern where dev->power.wakeirq is read and checked for NULL outside the lock. If two callers invoke this function concurrently, both might see a valid pointer and proceed. This could result in a double-free when the second caller acquires the lock and tries to release the same object. Address this by removing the lockless check of dev->power.wakeirq. Instead, acquire dev->power.lock immediately to ensure the check and the subsequent operations are atomic. If dev->power.wakeirq is NULL under the lock, simply unlock and return. This guarantees that concurrent calls cannot race to free the same object. Based on a quick scan of current users, I did not find an actual bug as drivers seem to rely on their own synchronization. However, since asynchronous usage patterns exist (e.g., in drivers/net/wireless/ti/wlcore), I believe a race is theoretically possible if the API is used less carefully in the future. This change hardens the API to be robust against such cases. Fixes: 4990d4fe327b ("PM / Wakeirq: Add automated device wake IRQ handling") Signed-off-by: Gui-Dong Han Link: https://patch.msgid.link/20260203031943.1924-1-hanguidong02@gmail.com Signed-off-by: Rafael J. Wysocki Signed-off-by: Sasha Levin --- drivers/base/power/wakeirq.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/base/power/wakeirq.c b/drivers/base/power/wakeirq.c index ab6eced7f5762..0328ee03c1bfc 100644 --- a/drivers/base/power/wakeirq.c +++ b/drivers/base/power/wakeirq.c @@ -83,13 +83,16 @@ EXPORT_SYMBOL_GPL(dev_pm_set_wake_irq); */ void dev_pm_clear_wake_irq(struct device *dev) { - struct wake_irq *wirq = dev->power.wakeirq; + struct wake_irq *wirq; unsigned long flags; - if (!wirq) + spin_lock_irqsave(&dev->power.lock, flags); + wirq = dev->power.wakeirq; + if (!wirq) { + spin_unlock_irqrestore(&dev->power.lock, flags); return; + } - spin_lock_irqsave(&dev->power.lock, flags); device_wakeup_detach_irq(dev); dev->power.wakeirq = NULL; spin_unlock_irqrestore(&dev->power.lock, flags); -- 2.51.0