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 6ABE838DD8; Thu, 28 Sep 2023 13:12:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5ED3BC433C7; Thu, 28 Sep 2023 13:12:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1695906727; bh=+1zU6l1Sj4Tu/8nppmaxE6SIjasiJ7VsM8uSjK5Nd90=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ELxue2D7+j8mxYN/FOFmFVbPZov0lrpHxH19stQ+e5Oggjfoc+YPse3e+vUryhgNy m9O+lKTojWNjuv7eJkQyM62DwKXgkAGYa+9MqweXsiXRCpvADEJZlyLaea2onPHlFO hL8LNucNTs1dLlIvi7T4vQ3wRqAUp666hdpuoMdS3T4R/XOqokUeIVf8bnSmCVjaVT yKaJQggiPrkEf9Wi9Hh93Q4TKuNStwhPWQbtfROnDL3Pf4ov/LZLwZYe2aSafnUr39 +SpLbkgQlmWsx8Imuwi5dFmDmNN3qP6N680uO8D9YU1ShgK03VRXBEFPobaHY9uq9Q a3aqWIfoAF54w== Date: Thu, 28 Sep 2023 15:11:45 +0200 From: Simon Horman To: Shigeru Yoshida Cc: steve.glendinning@shawell.net, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, syzbot+6966546b78d050bb0b5d@syzkaller.appspotmail.com Subject: Re: [PATCH] net: usb: smsc75xx: Fix uninit-value access in __smsc75xx_read_reg Message-ID: <20230928131145.GK24230@kernel.org> References: <20230923173549.3284502-1-syoshida@redhat.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230923173549.3284502-1-syoshida@redhat.com> On Sun, Sep 24, 2023 at 02:35:49AM +0900, Shigeru Yoshida wrote: > syzbot reported the following uninit-value access issue: > > ===================================================== > BUG: KMSAN: uninit-value in smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:975 [inline] > BUG: KMSAN: uninit-value in smsc75xx_bind+0x5c9/0x11e0 drivers/net/usb/smsc75xx.c:1482 > CPU: 0 PID: 8696 Comm: kworker/0:3 Not tainted 5.8.0-rc5-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > Workqueue: usb_hub_wq hub_event > Call Trace: > __dump_stack lib/dump_stack.c:77 [inline] > dump_stack+0x21c/0x280 lib/dump_stack.c:118 > kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 > __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 > smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:975 [inline] > smsc75xx_bind+0x5c9/0x11e0 drivers/net/usb/smsc75xx.c:1482 > usbnet_probe+0x1152/0x3f90 drivers/net/usb/usbnet.c:1737 > usb_probe_interface+0xece/0x1550 drivers/usb/core/driver.c:374 > really_probe+0xf20/0x20b0 drivers/base/dd.c:529 > driver_probe_device+0x293/0x390 drivers/base/dd.c:701 > __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 > bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 > __device_attach+0x4e2/0x7f0 drivers/base/dd.c:873 > device_initial_probe+0x4a/0x60 drivers/base/dd.c:920 > bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491 > device_add+0x3b0e/0x40d0 drivers/base/core.c:2680 > usb_set_configuration+0x380f/0x3f10 drivers/usb/core/message.c:2032 > usb_generic_driver_probe+0x138/0x300 drivers/usb/core/generic.c:241 > usb_probe_device+0x311/0x490 drivers/usb/core/driver.c:272 > really_probe+0xf20/0x20b0 drivers/base/dd.c:529 > driver_probe_device+0x293/0x390 drivers/base/dd.c:701 > __device_attach_driver+0x63f/0x830 drivers/base/dd.c:807 > bus_for_each_drv+0x2ca/0x3f0 drivers/base/bus.c:431 > __device_attach+0x4e2/0x7f0 drivers/base/dd.c:873 > device_initial_probe+0x4a/0x60 drivers/base/dd.c:920 > bus_probe_device+0x177/0x3d0 drivers/base/bus.c:491 > device_add+0x3b0e/0x40d0 drivers/base/core.c:2680 > usb_new_device+0x1bd4/0x2a30 drivers/usb/core/hub.c:2554 > hub_port_connect drivers/usb/core/hub.c:5208 [inline] > hub_port_connect_change drivers/usb/core/hub.c:5348 [inline] > port_event drivers/usb/core/hub.c:5494 [inline] > hub_event+0x5e7b/0x8a70 drivers/usb/core/hub.c:5576 > process_one_work+0x1688/0x2140 kernel/workqueue.c:2269 > worker_thread+0x10bc/0x2730 kernel/workqueue.c:2415 > kthread+0x551/0x590 kernel/kthread.c:292 > ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:293 > > Local variable ----buf.i87@smsc75xx_bind created at: > __smsc75xx_read_reg drivers/net/usb/smsc75xx.c:83 [inline] > smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:968 [inline] > smsc75xx_bind+0x485/0x11e0 drivers/net/usb/smsc75xx.c:1482 > __smsc75xx_read_reg drivers/net/usb/smsc75xx.c:83 [inline] > smsc75xx_wait_ready drivers/net/usb/smsc75xx.c:968 [inline] > smsc75xx_bind+0x485/0x11e0 drivers/net/usb/smsc75xx.c:1482 > > This issue is caused because usbnet_read_cmd() reads less bytes than requested > (zero byte in the reproducer). In this case, 'buf' is not properly filled. > > This patch fixes the issue by returning -ENODATA if usbnet_read_cmd() reads > less bytes than requested. > > Fixes: d0cad871703b ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver") > Reported-and-tested-by: syzbot+6966546b78d050bb0b5d@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=6966546b78d050bb0b5d > Signed-off-by: Shigeru Yoshida Reviewed-by: Simon Horman