@@ -1389,11 +1389,13 @@ static int functionfs_bind(struct ffs_data *ffs, struct usb_composite_dev *cdev)
ffs->ep0req->context = ffs;
lang = ffs->stringtabs;
- for (lang = ffs->stringtabs; *lang; ++lang) {
- struct usb_string *str = (*lang)->strings;
- int id = first_id;
- for (; str->s; ++id, ++str)
- str->id = id;
+ if (lang) {
+ for (; *lang; ++lang) {
+ struct usb_string *str = (*lang)->strings;
+ int id = first_id;
+ for (; str->s; ++id, ++str)
+ str->id = id;
+ }
}
ffs->gadget = cdev->gadget;
This is a note to let you know that I have just added a patch titled usb: gadget: f_fs: fix NULL pointer dereference when there are no strings to the linux-3.11.y-queue branch of the 3.11.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.11.y-queue If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.11.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Luis ------ From ad4204b65ecf6ecd2f736fffb30a33f9d9065651 Mon Sep 17 00:00:00 2001 From: Michal Nazarewicz <mina86@mina86.com> Date: Tue, 17 Jun 2014 17:47:41 +0200 Subject: usb: gadget: f_fs: fix NULL pointer dereference when there are no strings MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit f0688c8b81d2ea239c3fb0b848f623b579238d99 upstream. If the descriptors do not need any strings and user space sends empty set of strings, the ffs->stringtabs field remains NULL. Thus *ffs->stringtabs in functionfs_bind leads to a NULL pointer dereferenece. The bug was introduced by commit [fd7c9a007f: “use usb_string_ids_n()”]. While at it, remove double initialisation of lang local variable in that function. ffs->strings_count does not need to be checked in any way since in the above scenario it will remain zero and usb_string_ids_n() is a no-operation when colled with 0 argument. Signed-off-by: Michal Nazarewicz <mina86@mina86.com> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- drivers/usb/gadget/f_fs.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) -- 1.9.1