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 041A1379EF1 for ; Sat, 28 Feb 2026 18:07:39 +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=1772302059; cv=none; b=VdbzH+bXafdfJi3ZEnDi4wtZGYM2jj8WDJsmobZGlTQW0PndmSOHnSmY1IDKvWrRtsv+NlVAjx3TlWNmt5wfdrAM0lTkydV47sagn+JOM6IiV/u4mvmQr36WJPinlO+sFLdXpyNtzksgs4Z3y0UGwhC7U4yHBaWhJFRvKgj4GuI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1772302059; c=relaxed/simple; bh=gwPP/rU0FUDfD4HVpfrNP3CsvnVCy5pYUrwiIjCR16g=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=gtqFZGg6vB8Yo8YMQgx+qlaBnC6/WB0bnfKBA4Z57MGLpkDO/IlWEbArgDihdMixB/mM2JnaB+p04IN6OjhzoK4Uk0PB7DZ1NyN7fQv8bWy4iTciQrR2odwedRelDCMp87MfIGYhVNNWVeZGIvHVeIq2IhTJcRmca3YGP6zIsN0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=q5U51+Ky; 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="q5U51+Ky" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6C1B3C116D0; Sat, 28 Feb 2026 18:07:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1772302058; bh=gwPP/rU0FUDfD4HVpfrNP3CsvnVCy5pYUrwiIjCR16g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=q5U51+Ky6Tv2EOp7pbt5HH4pxNu8JOPrew2Vxef149U/sQc/hlmNmd/kvCHwYF+MY p9nV48aIlYu7lLYGp0kB6qfFOwHGixTEnInySlczvT5oLxoB/I2Qxdy+dkq7QYB3o9 upbSTY4AGUJ9uEJ9NWJfifbMSFArtyZAz4BRkhpPH2QTuxxW3yM/CZA6bsX/JZJtKF Zv+Mdp6DjicPhpiC0g6+Q8qqXUf0Plw9TZJM6UkRhDrx2r3ivClOhYklrNnvS9JkKb Kvt2aSD+lgZnjEL9umjZ9YyxB0DYCvD8YOqmeMZEfg89cLwxQZnBsIi80xu9fMazFJ /+sY7LB4Uhdew== From: Sasha Levin To: patches@lists.linux.dev Cc: Gui-Dong Han , "Rafael J. Wysocki" , Sasha Levin Subject: [PATCH 6.6 035/283] PM: sleep: wakeirq: harden dev_pm_clear_wake_irq() against races Date: Sat, 28 Feb 2026 13:02:57 -0500 Message-ID: <20260228180709.1583486-35-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260228180709.1583486-1-sashal@kernel.org> References: <20260228180709.1583486-1-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 5a5a9e978e85f..ddbe9cc91d23d 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