7fafcfdf63
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 ad0d1a058e
("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: ad0d1a058e ("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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
71 lines
2.2 KiB
C
71 lines
2.2 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* u_f.h
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*
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* Utility definitions for USB functions
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*
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* Copyright (c) 2013 Samsung Electronics Co., Ltd.
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* http://www.samsung.com
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*
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* Author: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
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*/
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#ifndef __U_F_H__
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#define __U_F_H__
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#include <linux/usb/gadget.h>
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/* Variable Length Array Macros **********************************************/
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#define vla_group(groupname) size_t groupname##__next = 0
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#define vla_group_size(groupname) groupname##__next
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#define vla_item(groupname, type, name, n) \
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size_t groupname##_##name##__offset = ({ \
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size_t align_mask = __alignof__(type) - 1; \
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size_t offset = (groupname##__next + align_mask) & ~align_mask;\
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size_t size = (n) * sizeof(type); \
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groupname##__next = offset + size; \
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offset; \
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})
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#define vla_item_with_sz(groupname, type, name, n) \
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size_t groupname##_##name##__sz = (n) * sizeof(type); \
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size_t groupname##_##name##__offset = ({ \
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size_t align_mask = __alignof__(type) - 1; \
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size_t offset = (groupname##__next + align_mask) & ~align_mask;\
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size_t size = groupname##_##name##__sz; \
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groupname##__next = offset + size; \
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offset; \
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})
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#define vla_ptr(ptr, groupname, name) \
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((void *) ((char *)ptr + groupname##_##name##__offset))
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struct usb_ep;
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struct usb_request;
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/**
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* alloc_ep_req - returns a usb_request allocated by the gadget driver and
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* allocates the request's buffer.
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*
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* @ep: the endpoint to allocate a usb_request
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* @len: usb_requests's buffer suggested size
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*
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* In case @ep direction is OUT, the @len will be aligned to ep's
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* wMaxPacketSize. In order to avoid memory leaks or drops, *always* use
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* usb_requests's length (req->length) to refer to the allocated buffer size.
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* Requests allocated via alloc_ep_req() *must* be freed by free_ep_req().
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*/
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struct usb_request *alloc_ep_req(struct usb_ep *ep, size_t len);
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/* Frees a usb_request previously allocated by alloc_ep_req() */
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static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req)
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{
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WARN_ON(req->buf == NULL);
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kfree(req->buf);
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req->buf = NULL;
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usb_ep_free_request(ep, req);
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}
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#endif /* __U_F_H__ */
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