From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 404F743B6E7; Mon, 17 Aug 2026 14:49:11 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786978156; cv=none; b=mtCunMIb+yFS0sE/q1Udo42L3yBXoWeypCAH9OVqheVT4yyn+gy7O9A5iwy94R/a0ykmKoaQ/cHlBN8okfqIX8WNa7Tpu5SIIrZRI6YevWThXPVzt2OygsxrdH1Wj76l1hvDBJu+OYFK3fEFcDr5NJhcmM5yhbpErvKJRYKskQo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1786978156; c=relaxed/simple; bh=riQaZL3mmp4SdBd3jhQKYx3an6ju8mY7CA70ZhU44Vc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=R0TEe7fTUY8XfNz60Vt2+aW/Qe14itXVxnWL2Grp7oABgwhaKjp5c6WxkmwuJcWsn/aCHzL/+apyPiF4aaBmdb/9GqD5hiCkGxhF6aeTgXLyGjZr1GcDMV3+u76zzFBq2cHXnCpjmGs+IO20uQv7bfCLajKyo5gEnw7LMZkB52w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=qik7trvh; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="qik7trvh" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B030B1F000E9; Mon, 17 Aug 2026 14:49:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1786978148; bh=uqVYyfcbaD1nG4M4g4tpbDjU4KySU5/vwiDVXdz2A4U=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=qik7trvhY2SH7tP4FxnG4so86Ax9MLD+Ef2wQvKLFKKlYcLPciM9vG5vCRQo8cA+0 MVObxjjE2XtmQFIMJVnMRglgHIUUO1O77MyUj1e4lTNrNVDqlsIN77ye+YgoWxcl4s cGsA5P00HawDHmUqidcBYAA7XFPgoy7tdjWACgBo= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Doruk Tan Ozturk , Jakub Kicinski Subject: [PATCH 6.12 081/181] net: usb: ipheth: fix carrier_work UAF on disconnect Date: Mon, 17 Aug 2026 15:32:55 +0200 Message-ID: <20260817132538.630235576@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260817132535.394764707@linuxfoundation.org> References: <20260817132535.394764707@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 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Doruk Tan Ozturk commit fde39b8a521780391fb4e5bda2c0aa4928947f12 upstream. ipheth_sndbulk_callback() re-arms the carrier-check work on any non-zero URB status: else schedule_delayed_work(&dev->carrier_work, 0); Nothing ties that to the interface being up, so the work can be armed again after ipheth_close() has already drained it, and stay armed until the netdev whose private area embeds it is freed. On unplug with a TX URB in flight, ipheth_disconnect() drains the work through unregister_netdev() -> ipheth_close() -> cancel_delayed_work_sync() and only then calls ipheth_kill_urbs(). usb_kill_urb() completes the in-flight TX URB with -ENOENT, so ipheth_sndbulk_callback() runs after the drain and re-arms carrier_work. The same completion also re-arms the work if the interface is only brought down while a TX URB is in flight, and ipheth_carrier_check_work() then keeps re-queueing itself once a second. unregister_netdev() does not call ipheth_close() for an already-down interface, so nothing drains it on the later unplug either. In both cases free_netdev() frees the netdev while carrier_work is still pending, and ipheth_carrier_check_work() dereferences freed memory. Tie the work to the interface state instead of chasing the completion: disable it in ipheth_close() and enable it in ipheth_open(), so a schedule_delayed_work() from the URB completion is a no-op whenever the interface is not up. disable_delayed_work_sync() also waits for a running instance, so it fully replaces the cancel_delayed_work_sync() it takes the place of. The work starts out disabled in ipheth_probe() so the enable/disable counts balance from the first open. Reproduced under KASAN on linux-next (next-20260731) with dummy_hcd and raw-gadget standing in for the device, driving the second path above (the interface is already down, so unregister_netdev() does not call ipheth_close()): 15 of 15 unpatched boots report a slab-use-after-free in __run_timers(), freed by ipheth_disconnect() and re-armed from ipheth_sndbulk_callback() via queue_delayed_work_on(). The same trigger on a kernel differing only by this patch reports 0 of 15, and the carrier check still functions across open/close cycles. The reproducer needs an attached USB device that stops draining bulk OUT, plus a link down and unplug, driven as root. It is not a privilege boundary crossing and no exploit primitive was developed. Found by 0sec (https://0sec.ai). Fixes: bb1b40c7cb86 ("usbnet: ipheth: prevent TX queue timeouts when device not ready") Cc: stable@vger.kernel.org Signed-off-by: Doruk Tan Ozturk Link: https://patch.msgid.link/20260802120602.42595-1-doruk@0sec.ai Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- drivers/net/usb/ipheth.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) --- a/drivers/net/usb/ipheth.c +++ b/drivers/net/usb/ipheth.c @@ -490,6 +490,7 @@ static int ipheth_open(struct net_device if (retval) return retval; + enable_delayed_work(&dev->carrier_work); schedule_delayed_work(&dev->carrier_work, IPHETH_CARRIER_CHECK_TIMEOUT); return retval; } @@ -499,7 +500,11 @@ static int ipheth_close(struct net_devic struct ipheth_device *dev = netdev_priv(net); netif_stop_queue(net); - cancel_delayed_work_sync(&dev->carrier_work); + /* A TX URB can still complete with an error after this point and + * try to re-arm the carrier work. Disable it instead of cancelling + * it, so that such a schedule_delayed_work() is a no-op. + */ + disable_delayed_work_sync(&dev->carrier_work); return 0; } @@ -633,6 +638,10 @@ static int ipheth_probe(struct usb_inter } INIT_DELAYED_WORK(&dev->carrier_work, ipheth_carrier_check_work); + /* Armed only between ipheth_open() and ipheth_close(). Start out + * disabled so the enable/disable counts balance from the first open. + */ + disable_delayed_work(&dev->carrier_work); retval = ipheth_alloc_urbs(dev); if (retval) {