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 2974218B0A; Wed, 25 Feb 2026 01:34:25 +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=1771983265; cv=none; b=huiPCcyoOMHSHtpVehmFKjM1m5Cl6AxCvRHIux108o7tB03Zj/QyhII3b41LPGGsR6W3O9lnxXQ779fpwlW0AYO73C3M9qAN6qO9yJt1+AHjMmmxegQ8dyINJ+3r2DNnF3u17tVMTbSBd+cnW+ezIKiCp+FAs9JW0tY2D+979Y4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771983265; c=relaxed/simple; bh=DPwHtrFjDeYAVDSePcu4J4Qb6ZcokRbjknEDYprJjOc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=btbz3cmcVzE/+ArNOd2w3C9y8uI3t1D0k5N4xzFCfvddU5d9ZIjeuj7aV1ykVYtOwIjPLnsJdS0UypQ9fBJSqBj5pSwVxHV0ibo4cfOEa1aZIg7gDlxqGllH+Qb+1Fjmk9O/BGpOZ53AuP+ZdR71VySHEOnryL7YsaJ3ILTDiWA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=2vZjfKCg; 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="2vZjfKCg" Received: by smtp.kernel.org (Postfix) with ESMTPSA id ECE28C116D0; Wed, 25 Feb 2026 01:34:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1771983265; bh=DPwHtrFjDeYAVDSePcu4J4Qb6ZcokRbjknEDYprJjOc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=2vZjfKCgthoLhjcuiocJyAHgDoK7o2yT0S89Wksy7sJrTozbhgFDVstrp2VnInrSm ABoMXd2K/VXkxsaGj0hIW8kky/MAwpFHTuESwG2uk/fluzbaaSv7QXdrjuY9qjWoP4 R7Zu7MjthzBMC2fMdNlK041FBPuY9lcFoWHGbhF4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Votokina Victoria , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.19 406/781] nfc: hci: shdlc: Stop timers and work before freeing context Date: Tue, 24 Feb 2026 17:18:35 -0800 Message-ID: <20260225012409.661419848@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260225012359.695468795@linuxfoundation.org> References: <20260225012359.695468795@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Votokina Victoria [ Upstream commit c9efde1e537baed7648a94022b43836a348a074f ] llc_shdlc_deinit() purges SHDLC skb queues and frees the llc_shdlc structure while its timers and state machine work may still be active. Timer callbacks can schedule sm_work, and sm_work accesses SHDLC state and the skb queues. If teardown happens in parallel with a queued/running work item, it can lead to UAF and other shutdown races. Stop all SHDLC timers and cancel sm_work synchronously before purging the queues and freeing the context. Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 4a61cd6687fc ("NFC: Add an shdlc llc module to llc core") Signed-off-by: Votokina Victoria Link: https://patch.msgid.link/20260203113158.2008723-1-Victoria.Votokina@kaspersky.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/nfc/hci/llc_shdlc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/nfc/hci/llc_shdlc.c b/net/nfc/hci/llc_shdlc.c index 4fc37894860c9..08c8aa1530d8a 100644 --- a/net/nfc/hci/llc_shdlc.c +++ b/net/nfc/hci/llc_shdlc.c @@ -762,6 +762,14 @@ static void llc_shdlc_deinit(struct nfc_llc *llc) { struct llc_shdlc *shdlc = nfc_llc_get_data(llc); + timer_shutdown_sync(&shdlc->connect_timer); + timer_shutdown_sync(&shdlc->t1_timer); + timer_shutdown_sync(&shdlc->t2_timer); + shdlc->t1_active = false; + shdlc->t2_active = false; + + cancel_work_sync(&shdlc->sm_work); + skb_queue_purge(&shdlc->rcv_q); skb_queue_purge(&shdlc->send_q); skb_queue_purge(&shdlc->ack_pending_q); -- 2.51.0