On Tue, Aug 20, 2019 at 10:45:13AM -0700, Mark Salyzyn wrote:
From: "Yavuz, Tuba" tuba@ece.ufl.edu
cherry pick from commit 7fafcfdf6377b18b2a726ea554d6e593ba44349f ("USB: gadget: f_midi: fixing a possible double-free in f_midi") Removing 'return err;' from conflict.
It looks like there is a possibility of a double-free vulnerability on an error path of the f_midi_set_alt function in the f_midi driver. If the path is feasible then free_ep_req gets called twice:
req->complete = f_midi_complete; err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC); => ... usb_gadget_giveback_request => f_midi_complete (CALLBACK) (inside f_midi_complete, for various cases of status) free_ep_req(ep, req); // first kfree if (err) { ERROR(midi, "%s: couldn't enqueue request: %d\n", midi->out_ep->name, err); free_ep_req(midi->out_ep, req); // second kfree return err; }The double-free possibility was introduced with commit ad0d1a058eac ("usb: gadget: f_midi: fix leak on failed to enqueue out requests").
Found by MOXCAFE tool.
Signed-off-by: Tuba Yavuz tuba@ece.ufl.edu Fixes: ad0d1a058eac ("usb: gadget: f_midi: fix leak on failed to enqueue out requests") Acked-by: Felipe Balbi felipe.balbi@linux.intel.com Cc: stable stable@vger.kernel.org # 4.4.y
No signed-off-by from you?
Anyway, this is already in the 4.4.y queue and will be in the next release.
thanks,
greg k-h