linux-kernel - [ 18/26] USB: EHCI: fix bug in scheduling periodic split transfers

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]

Date:	Thu,  7 Feb 2013 16:57:46 -0800
From:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:	linux-kernel@...r.kernel.org
Cc:	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	stable@...r.kernel.org, Alan Stern <stern@...land.harvard.edu>
Subject: [ 18/26] USB: EHCI: fix bug in scheduling periodic split transfers

3.4-stable review patch.  If anyone has any objections, please let me know.

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

From: Alan Stern <stern@...land.harvard.edu>

commit 3e619d04159be54b3daa0b7036b0ce9e067f4b5d upstream.

This patch (as1654) fixes a very old bug in ehci-hcd, connected with
scheduling of periodic split transfers.  The calculations for
full/low-speed bus usage are all carried out after the correction for
bit-stuffing has been applied, but the values in the max_tt_usecs
array assume it hasn't been.  The array should allow for allocation of
up to 90% of the bus capacity, which is 900 us, not 780 us.

The symptom caused by this bug is that any isochronous transfer to a
full-speed device with a maxpacket size larger than about 980 bytes is
always rejected with a -ENOSPC error.

Signed-off-by: Alan Stern <stern@...land.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 drivers/usb/host/ehci-sched.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/usb/host/ehci-sched.c
+++ b/drivers/usb/host/ehci-sched.c
@@ -236,7 +236,7 @@ static inline unsigned char tt_start_ufr
 }

 static const unsigned char
-max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 30, 0 };
+max_tt_usecs[] = { 125, 125, 125, 125, 125, 125, 125, 25 };

 /* carryover low/fullspeed bandwidth that crosses uframe boundries */
 static inline void carryover_tt_bandwidth(unsigned short tt_usecs[8])

--
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/