linux-kernel - [PATCH 3.2 143/149] xhci: Fix race between ep halt and URB cancellation

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <lsq.1382345188.689153462@decadent.org.uk>
Date:	Mon, 21 Oct 2013 09:46:28 +0100
From:	Ben Hutchings <ben@...adent.org.uk>
To:	linux-kernel@...r.kernel.org, stable@...r.kernel.org
CC:	akpm@...ux-foundation.org, "Florian Wolter" <wolly84@....de>,
	"Sarah Sharp" <sarah.a.sharp@...ux.intel.com>
Subject: [PATCH 3.2 143/149] xhci: Fix race between ep halt and URB
 cancellation

3.2.52-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Florian Wolter <wolly84@....de>

commit 526867c3ca0caa2e3e846cb993b0f961c33c2abb upstream.

The halted state of a endpoint cannot be cleared over CLEAR_HALT from a
user process, because the stopped_td variable was overwritten in the
handle_stopped_endpoint() function. So the xhci_endpoint_reset() function will
refuse the reset and communication with device can not run over this endpoint.
https://bugzilla.kernel.org/show_bug.cgi?id=60699

Signed-off-by: Florian Wolter <wolly84@....de>
Signed-off-by: Sarah Sharp <sarah.a.sharp@...ux.intel.com>
Signed-off-by: Ben Hutchings <ben@...adent.org.uk>
---
 drivers/usb/host/xhci-ring.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

--- a/drivers/usb/host/xhci-ring.c
+++ b/drivers/usb/host/xhci-ring.c
@@ -879,8 +879,12 @@ remove_finished_td:
 		/* Otherwise ring the doorbell(s) to restart queued transfers */
 		ring_doorbell_for_active_rings(xhci, slot_id, ep_index);
 	}
-	ep->stopped_td = NULL;
-	ep->stopped_trb = NULL;
+
+	/* Clear stopped_td and stopped_trb if endpoint is not halted */
+	if (!(ep->ep_state & EP_HALTED)) {
+		ep->stopped_td = NULL;
+		ep->stopped_trb = NULL;
+	}
 
 	/*
 	 * Drop the lock and complete the URBs in the cancelled TD list.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/