This is a note to let you know that I've just added the patch titled usb: gadget: f_fs: add extra check before unregister_gadget_item to the 4.1-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-add-extra-check-before-unregister_gadget_item.patch and it can be found in the queue-4.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From f14e9ad17f46051b02bffffac2036486097de19e Mon Sep 17 00:00:00 2001 From: Rui Miguel Silva <rui.silva@xxxxxxxxxx> Date: Wed, 20 May 2015 14:52:40 +0100 Subject: usb: gadget: f_fs: add extra check before unregister_gadget_item From: Rui Miguel Silva <rui.silva@xxxxxxxxxx> commit f14e9ad17f46051b02bffffac2036486097de19e upstream. ffs_closed can race with configfs_rmdir which will call config_item_release, so add an extra check to avoid calling the unregister_gadget_item with an null gadget item. Signed-off-by: Rui Miguel Silva <rui.silva@xxxxxxxxxx> Signed-off-by: Felipe Balbi <balbi@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/usb/gadget/function/f_fs.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) --- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -3435,6 +3435,7 @@ done: static void ffs_closed(struct ffs_data *ffs) { struct ffs_dev *ffs_obj; + struct f_fs_opts *opts; ENTER(); ffs_dev_lock(); @@ -3449,8 +3450,13 @@ static void ffs_closed(struct ffs_data * ffs_obj->ffs_closed_callback) ffs_obj->ffs_closed_callback(ffs); - if (!ffs_obj->opts || ffs_obj->opts->no_configfs - || !ffs_obj->opts->func_inst.group.cg_item.ci_parent) + if (ffs_obj->opts) + opts = ffs_obj->opts; + else + goto done; + + if (opts->no_configfs || !opts->func_inst.group.cg_item.ci_parent + || !atomic_read(&opts->func_inst.group.cg_item.ci_kref.refcount)) goto done; unregister_gadget_item(ffs_obj->opts-> Patches currently in stable-queue which might be from rui.silva@xxxxxxxxxx are queue-4.1/usb-gadget-f_fs-add-extra-check-before-unregister_gadget_item.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html