Patch "usb: gadget: f_fs: Process all descriptors during bind" has been added to the 4.15-stable tree

This is a note to let you know that I've just added the patch titled

usb: gadget: f_fs: Process all descriptors during bind

to the 4.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
usb-gadget-f_fs-process-all-descriptors-during-bind.patch
and it can be found in the queue-4.15 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Jack Pham <[email protected]>
Date: Wed, 24 Jan 2018 00:11:53 -0800
Subject: usb: gadget: f_fs: Process all descriptors during bind

From: Jack Pham <[email protected]>

commit 6cf439e0d37463e42784271179c8a308fd7493c6 upstream.

During _ffs_func_bind(), the received descriptors are evaluated to prepare for binding with the gadget in order to allocate endpoints and optionally set up OS descriptors. However, the high- and super-speed descriptors are only parsed based on whether the gadget_is_dualspeed() and gadget_is_superspeed() calls are true, respectively.

This is a problem in case a userspace program always provides all of the {full,high,super,OS} descriptors when configuring a function. Then, for example if a gadget device is not capable of SuperSpeed, the call to ffs_do_descs() for the SS descriptors is skipped, resulting in an incorrect offset calculation for the vla_ptr when moving on to the OS descriptors that follow. This causes ffs_do_os_descs() to fail as it is now looking at the SS descriptors' offset within the raw_descs buffer instead.

_ffs_func_bind() should evaluate the descriptors unconditionally, so remove the checks for gadget speed.

---
 drivers/usb/gadget/function/f_fs.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

@@ -2976,10 +2976,8 @@ static int _ffs_func_bind(struct usb_con
 	struct ffs_data *ffs = func->ffs;
 
 	const int full = !!func->ffs->fs_descs_count;
-	const int high = gadget_is_dualspeed(func->gadget) &&
-		func->ffs->hs_descs_count;
-	const int super = gadget_is_superspeed(func->gadget) &&
-		func->ffs->ss_descs_count;
+	const int high = !!func->ffs->hs_descs_count;
+	const int super = !!func->ffs->ss_descs_count;
 
 	int fs_len, hs_len, ss_len, ret, i;
 	struct ffs_ep *eps_ptr;

Patches currently in stable-queue which might be from [email protected] are

queue-4.15/usb-gadget-f_fs-use-config_ep_by_speed.patch queue-4.15/usb-gadget-f_fs-process-all-descriptors-during-bind.patch