Linux-USB Archive on lore.kernel.org
 help / color / Atom feed
From: Mathias Nyman <mathias.nyman@linux.intel.com>
To: <gregkh@linuxfoundation.org>
Cc: <linux-usb@vger.kernel.org>,
	Mathias Nyman <mathias.nyman@linux.intel.com>,
	"# v5 . 3" <stable@vger.kernel.org>
Subject: [PATCH 8/8] xhci: Fix NULL pointer dereference in xhci_clear_tt_buffer_complete()
Date: Fri,  4 Oct 2019 14:59:33 +0300
Message-ID: <1570190373-30684-9-git-send-email-mathias.nyman@linux.intel.com> (raw)
In-Reply-To: <1570190373-30684-1-git-send-email-mathias.nyman@linux.intel.com>

udev stored in ep->hcpriv might be NULL if tt buffer is cleared
due to a halted control endpoint during device enumeration

xhci_clear_tt_buffer_complete is called by hub_tt_work() once it's
scheduled,  and by then usb core might have freed and allocated a
new udev for the next enumeration attempt.

Fixes: ef513be0a905 ("usb: xhci: Add Clear_TT_Buffer")
Cc: <stable@vger.kernel.org> # v5.3
Reported-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Mathias Nyman <mathias.nyman@linux.intel.com>
---
 drivers/usb/host/xhci.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
index 00f3804f7aa7..517ec3206f6e 100644
--- a/drivers/usb/host/xhci.c
+++ b/drivers/usb/host/xhci.c
@@ -5238,8 +5238,16 @@ static void xhci_clear_tt_buffer_complete(struct usb_hcd *hcd,
 	unsigned int ep_index;
 	unsigned long flags;
 
+	/*
+	 * udev might be NULL if tt buffer is cleared during a failed device
+	 * enumeration due to a halted control endpoint. Usb core might
+	 * have allocated a new udev for the next enumeration attempt.
+	 */
+
 	xhci = hcd_to_xhci(hcd);
 	udev = (struct usb_device *)ep->hcpriv;
+	if (!udev)
+		return;
 	slot_id = udev->slot_id;
 	ep_index = xhci_get_endpoint_index(&ep->desc);
 
-- 
2.7.4


  parent reply index

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-10-04 11:59 [PATCH 0/8] xhci fixes for usb-linus Mathias Nyman
2019-10-04 11:59 ` [PATCH 1/8] xhci: Fix false warning message about wrong bounce buffer write length Mathias Nyman
2019-10-04 11:59 ` [PATCH 2/8] xhci: Prevent device initiated U1/U2 link pm if exit latency is too long Mathias Nyman
2019-10-04 11:59 ` [PATCH 3/8] xhci: Check all endpoints for LPM timeout Mathias Nyman
2019-10-04 11:59 ` [PATCH 4/8] xhci: Fix USB 3.1 capability detection on early xHCI 1.1 spec based hosts Mathias Nyman
2019-10-04 11:59 ` [PATCH 5/8] usb: xhci: wait for CNR controller not ready bit in xhci resume Mathias Nyman
2019-10-04 11:59 ` [PATCH 6/8] xhci: Prevent deadlock when xhci adapter breaks during init Mathias Nyman
2019-10-04 11:59 ` [PATCH 7/8] xhci: Increase STS_SAVE timeout in xhci_suspend() Mathias Nyman
     [not found]   ` <20191006120750.5334F2087E@mail.kernel.org>
2019-10-07 18:51     ` Kai-Heng Feng
2019-10-04 11:59 ` Mathias Nyman [this message]
2019-10-07 14:02   ` [PATCH 8/8] xhci: Fix NULL pointer dereference in xhci_clear_tt_buffer_complete() Johan Hovold
2019-10-08  8:15     ` Mathias Nyman
2019-10-11 12:47       ` Mathias Nyman
2019-10-11 12:58         ` [RFT PATCH] xhci: Fix use-after-free regression in xhci clear hub TT implementation Mathias Nyman
2019-10-14 10:16           ` Johan Hovold
2019-10-14 13:18             ` Mathias Nyman

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1570190373-30684-9-git-send-email-mathias.nyman@linux.intel.com \
    --to=mathias.nyman@linux.intel.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=linux-usb@vger.kernel.org \
    --cc=stable@vger.kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-USB Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-usb/0 linux-usb/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-usb linux-usb/ https://lore.kernel.org/linux-usb \
		linux-usb@vger.kernel.org
	public-inbox-index linux-usb

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-usb


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git