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 C3C21383C6E for ; Tue, 12 May 2026 12:31:55 +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=1778589115; cv=none; b=owFTXWg+QuQNUqO15L+DarhQCyQw0jUmMPs9cGmme/8noz1akTEMhy/nIz43L+rgoX3CzIY+lIMwVV96MdbfKRjLkDiLBBFVcEJNREo3pfIV3WrXCbXduBaSkg9cyz29w25PhMSA1FyrV7BCUm0ZWpi/gLa8qD2HDImwjfCYhTo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778589115; c=relaxed/simple; bh=w9fGdY1ZEv1130+vBQ6odLEdxYqAO9Iz2Gb6K+3G1Ps=; h=Subject:To:Cc:From:Date:Message-ID; b=dReU/XLEMQNGScZ8CQHJ3XT9Xim8X03JA50ctI5Da+H+F/DddVWi8eiyWxuO1vi3tWTneGoneXi5ILGHDwvtL8Nhb9cTnfXHulIK7+Y3/AM3EABJREHa0JAV1oJqY81iVOsmXGzXLD6SZWGtxZ05haq6jG8XCaR7JX0yNK/VKrQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=WehyD6iu; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="WehyD6iu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5B73BC2BCF6; Tue, 12 May 2026 12:31:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1778589113; bh=w9fGdY1ZEv1130+vBQ6odLEdxYqAO9Iz2Gb6K+3G1Ps=; h=Subject:To:Cc:From:Date:From; b=WehyD6iu0TZSHRPZ4cmHy1lZEpR1zCf1G0vCF54PDvfTFAfwruyczdcUC3VAUJQ2V vnxjtUfwTr+kp+ZFIiU9l4OGyssfNfowpP5hLzbMVr6ptIULWodPMgn07zuxWklRKA EdGOeFmSlhcmpmz6XPP5MW3Aj5HMbw4GxxmTlf1o= Subject: FAILED: patch "[PATCH] ALSA: core: Serialize deferred fasync state checks" failed to apply to 6.6-stable tree To: cassiogabrielcontato@gmail.com,tiwai@suse.de Cc: From: Date: Tue, 12 May 2026 14:31:50 +0200 Message-ID: <2026051250-tattered-mulled-92f0@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 5337213381df578058e2e41da93cbd0e4639935f # git commit -s git send-email --to '' --in-reply-to '2026051250-tattered-mulled-92f0@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 5337213381df578058e2e41da93cbd0e4639935f Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?C=C3=A1ssio=20Gabriel?= Date: Wed, 6 May 2026 00:34:47 -0300 Subject: [PATCH] ALSA: core: Serialize deferred fasync state checks MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit snd_fasync_helper() updates fasync->on under snd_fasync_lock, and snd_fasync_work_fn() now also evaluates fasync->on under the same lock. snd_kill_fasync() still tests the flag before taking the lock, leaving an unsynchronized read against FASYNC enable/disable updates. Move the enabled-state check into the locked section. Also clear fasync->on under snd_fasync_lock in snd_fasync_free() before unlinking the pending entry. Together with the locked sender-side check, this publishes teardown before flushing the deferred work and prevents a racing sender from requeueing the entry after free has started. Fixes: ef34a0ae7a26 ("ALSA: core: Add async signal helpers") Fixes: 8146cd333d23 ("ALSA: core: Fix potential data race at fasync handling") Cc: stable@vger.kernel.org Signed-off-by: Cássio Gabriel Link: https://patch.msgid.link/20260506-alsa-core-fasync-on-lock-v1-1-ea48c77d6ca4@gmail.com Signed-off-by: Takashi Iwai diff --git a/sound/core/misc.c b/sound/core/misc.c index 5aca09edf971..833124c8e4fa 100644 --- a/sound/core/misc.c +++ b/sound/core/misc.c @@ -148,9 +148,11 @@ EXPORT_SYMBOL_GPL(snd_fasync_helper); void snd_kill_fasync(struct snd_fasync *fasync, int signal, int poll) { - if (!fasync || !fasync->on) + if (!fasync) return; guard(spinlock_irqsave)(&snd_fasync_lock); + if (!fasync->on) + return; fasync->signal = signal; fasync->poll = poll; list_move(&fasync->list, &snd_fasync_list); @@ -163,8 +165,10 @@ void snd_fasync_free(struct snd_fasync *fasync) if (!fasync) return; - scoped_guard(spinlock_irq, &snd_fasync_lock) + scoped_guard(spinlock_irq, &snd_fasync_lock) { + fasync->on = 0; list_del_init(&fasync->list); + } flush_work(&snd_fasync_work); kfree(fasync);