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 CE5F38F57 for ; Sun, 16 Jul 2023 20:49:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5331EC433C7; Sun, 16 Jul 2023 20:49:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689540540; bh=b575pVZTQFRMo/Hrj7Ee35AI6sOk8zBbmfES1jRteZY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=S7rMewV+5Txyq1SLFr/ONXiTT+CnVX/XpuFZouvqglDLzWjtpwQ+psTEWV8/ZlpQ0 BFlXEpyCsq3wSlQHWhCcAlJPtz3P7Q62tTL+30jIeUxdRsshW0R1f2RIqniAMS7xqA /L24IMJ8uece19TrVp0VIt6keSHyYIRFAwbbtQY8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+27b0b464864741b18b99@syzkaller.appspotmail.com, Duoming Zhou , Hans Verkuil , Sasha Levin Subject: [PATCH 6.1 399/591] media: usb: siano: Fix warning due to null work_func_t function pointer Date: Sun, 16 Jul 2023 21:48:58 +0200 Message-ID: <20230716194934.242614987@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194923.861634455@linuxfoundation.org> References: <20230716194923.861634455@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Duoming Zhou [ Upstream commit 6f489a966fbeb0da63d45c2c66a8957eab604bf6 ] The previous commit ebad8e731c1c ("media: usb: siano: Fix use after free bugs caused by do_submit_urb") adds cancel_work_sync() in smsusb_stop_streaming(). But smsusb_stop_streaming() may be called, even if the work_struct surb->wq has not been initialized. As a result, the warning will occur. One of the processes that could lead to warning is shown below: smsusb_probe() smsusb_init_device() if (!dev->in_ep || !dev->out_ep || align < 0) { smsusb_term_device(intf); smsusb_stop_streaming() cancel_work_sync(&dev->surbs[i].wq); __cancel_work_timer() __flush_work() if (WARN_ON(!work->func)) // work->func is null The log reported by syzbot is shown below: WARNING: CPU: 0 PID: 897 at kernel/workqueue.c:3066 __flush_work+0x798/0xa80 kernel/workqueue.c:3063 Modules linked in: CPU: 0 PID: 897 Comm: kworker/0:2 Not tainted 6.2.0-rc1-syzkaller #0 RIP: 0010:__flush_work+0x798/0xa80 kernel/workqueue.c:3066 ... RSP: 0018:ffffc9000464ebf8 EFLAGS: 00010246 RAX: 1ffff11002dbb420 RBX: 0000000000000021 RCX: 1ffffffff204fa4e RDX: dffffc0000000000 RSI: 0000000000000001 RDI: ffff888016dda0e8 RBP: ffffc9000464ed98 R08: 0000000000000001 R09: ffffffff90253b2f R10: 0000000000000001 R11: 0000000000000000 R12: ffff888016dda0e8 R13: ffff888016dda0e8 R14: ffff888016dda100 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd4331efe8 CR3: 000000000b48e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __cancel_work_timer+0x315/0x460 kernel/workqueue.c:3160 smsusb_stop_streaming drivers/media/usb/siano/smsusb.c:182 [inline] smsusb_term_device+0xda/0x2d0 drivers/media/usb/siano/smsusb.c:344 smsusb_init_device+0x400/0x9ce drivers/media/usb/siano/smsusb.c:419 smsusb_probe+0xbbd/0xc55 drivers/media/usb/siano/smsusb.c:567 ... This patch adds check before cancel_work_sync(). If surb->wq has not been initialized, the cancel_work_sync() will not be executed. Reported-by: syzbot+27b0b464864741b18b99@syzkaller.appspotmail.com Fixes: ebad8e731c1c ("media: usb: siano: Fix use after free bugs caused by do_submit_urb") Signed-off-by: Duoming Zhou Signed-off-by: Hans Verkuil Signed-off-by: Sasha Levin --- drivers/media/usb/siano/smsusb.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/media/usb/siano/smsusb.c b/drivers/media/usb/siano/smsusb.c index 6f443c542c6da..640737d3b8aeb 100644 --- a/drivers/media/usb/siano/smsusb.c +++ b/drivers/media/usb/siano/smsusb.c @@ -179,7 +179,8 @@ static void smsusb_stop_streaming(struct smsusb_device_t *dev) for (i = 0; i < MAX_URBS; i++) { usb_kill_urb(&dev->surbs[i].urb); - cancel_work_sync(&dev->surbs[i].wq); + if (dev->surbs[i].wq.func) + cancel_work_sync(&dev->surbs[i].wq); if (dev->surbs[i].cb) { smscore_putbuffer(dev->coredev, dev->surbs[i].cb); -- 2.39.2