]> git.itanic.dy.fi Git - linux-stable/commit
usb: gadget: mass_storage: Fix cdrom data transfers on MAC-OS
authorKrishna Kurapati <quic_kriskura@quicinc.com>
Sat, 27 Aug 2022 03:15:10 +0000 (08:45 +0530)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 15 Sep 2022 10:04:52 +0000 (12:04 +0200)
commitbb87fe79bc2c308a3d8c6c1c1c32f0f9f55d3668
tree4625ec3ffe3a5158593a8ecf92a5cab46fed63f4
parentdf1875084898b15cbc42f712e93d7f113ae6271b
usb: gadget: mass_storage: Fix cdrom data transfers on MAC-OS

commit 9d4dc16ec71bd6368548e9743223e449b4377fc7 upstream.

During cdrom emulation, the response to read_toc command must contain
the cdrom address as the number of sectors (2048 byte sized blocks)
represented either as an absolute value (when MSF bit is '0') or in
terms of PMin/PSec/PFrame (when MSF bit is set to '1'). Incase of
cdrom, the fsg_lun_open call sets the sector size to 2048 bytes.

When MAC OS sends a read_toc request with MSF set to '1', the
store_cdrom_address assumes that the address being provided is the
LUN size represented in 512 byte sized blocks instead of 2048. It
tries to modify the address further to convert it to 2048 byte sized
blocks and store it in MSF format. This results in data transfer
failures as the cdrom address being provided in the read_toc response
is incorrect.

Fixes: 3f565a363cee ("usb: gadget: storage: adapt logic block size to bound block devices")
Cc: stable@vger.kernel.org
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Krishna Kurapati <quic_kriskura@quicinc.com>
Link: https://lore.kernel.org/r/1661570110-19127-1-git-send-email-quic_kriskura@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/gadget/function/storage_common.c