USB: serial: visor: handle potential invalid device configuration
authorGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Sun, 29 Apr 2018 15:41:55 +0000 (17:41 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 9 May 2018 07:51:54 +0000 (09:51 +0200)
commit0cc49bb627addd738879950d19a3ba3127c729cd
tree6dbe9bcd7715e0bb80346686b81ea970edf44dee
parent0799a0ea96e4923f52f85fe315b62e9176a3319c
USB: serial: visor: handle potential invalid device configuration

commit 4842ed5bfcb9daf6660537d70503c18d38dbdbb8 upstream.

If we get an invalid device configuration from a palm 3 type device, we
might incorrectly parse things, and we have the potential to crash in
"interesting" ways.

Fix this up by verifying the size of the configuration passed to us by
the device, and only if it is correct, will we handle it.

Note that this also fixes an information leak of slab data.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Konovalov <andreyknvl@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ johan: add comment about the info leak ]
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/usb/serial/visor.c