From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4/AkiaP/NBPUc7maBGi7ikIibEgcSknX/Bof6fBTJCSTcv4TptnQ1TRjRT2ykHLY8DItWBK ARC-Seal: i=1; a=rsa-sha256; t=1524406300; cv=none; d=google.com; s=arc-20160816; b=0fLV8MujfQEu3ExNnzXbqYJWboOP1d8/m07FEaEcEaEVOxelC0L+YeFRq7LLPCl+ju 22xN978pQAEZRb3T4mL4k8O1364BZCUHGifoGMXOyERvJ3vta2WZYftrSq/0yKImwL4d XbmTQ1mMMsrCm/lX8/R5/9uWrgWI2K/Z7MSO8afN9IIoGXE4f1tx+QWrniNorynEyMQb jl1k0rljIHPVB9qEFW/W7g7DzLQHvPM9INL6QmJnort7z5HLO0wltJo6k0saIo6cTKHE NcY61uLLPLAJwmqdhKR8qOzg5H0cqBZ3OaQTo4a8ArvWYgKHdfIZ6K3vtGSLH6dbKeOX wz+w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=JR7DsSgJe2xwe1v58mQHtYb4i1g8aGgMjBfCIOiuykI=; b=N8E0PibTZDCgXg6zldCVDtguZX/9N5R+EiMAhMCj1ciHPA7bi4+eR8cbNbkv2CeO4r kYZqFI4UY3QquP8W5Vvrd3ph5tFsF6Kl6arT7xO1sX7IurlEKk6GANQaNtt19EaM7n2A f0/KZhbSUDywxG+NRR3Ow8b7supqHSj8UBZfJ3R8H15f1vgQChVOXHtx6L5R40X1n17Y BF6mL66MjG5o489eTnJDDERGri9ydS/IRyLp2Ob3tq/GcyHJHqlFu5q2wT0fOEtULex4 IVFES1D0Uwr/QgNm4vIjZbXpVJsgAqk2H7K5MsSPo9hMiehHmOndIEQvRnbO5c4tgflm M0XA== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tuba Yavuz , Felipe Balbi Subject: [PATCH 4.9 20/95] USB: gadget: f_midi: fixing a possible double-free in f_midi Date: Sun, 22 Apr 2018 15:52:49 +0200 Message-Id: <20180422135211.266586357@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180422135210.432103639@linuxfoundation.org> References: <20180422135210.432103639@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1598454885662324670?= X-GMAIL-MSGID: =?utf-8?q?1598455860869216067?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Yavuz, Tuba commit 7fafcfdf6377b18b2a726ea554d6e593ba44349f upstream. 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 Fixes: ad0d1a058eac ("usb: gadget: f_midi: fix leak on failed to enqueue out requests") Acked-by: Felipe Balbi Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/gadget/function/f_midi.c | 3 ++- drivers/usb/gadget/u_f.h | 2 ++ 2 files changed, 4 insertions(+), 1 deletion(-) --- a/drivers/usb/gadget/function/f_midi.c +++ b/drivers/usb/gadget/function/f_midi.c @@ -389,7 +389,8 @@ static int f_midi_set_alt(struct usb_fun if (err) { ERROR(midi, "%s: couldn't enqueue request: %d\n", midi->out_ep->name, err); - free_ep_req(midi->out_ep, req); + if (req->buf != NULL) + free_ep_req(midi->out_ep, req); return err; } } --- a/drivers/usb/gadget/u_f.h +++ b/drivers/usb/gadget/u_f.h @@ -64,7 +64,9 @@ struct usb_request *alloc_ep_req(struct /* Frees a usb_request previously allocated by alloc_ep_req() */ static inline void free_ep_req(struct usb_ep *ep, struct usb_request *req) { + WARN_ON(req->buf == NULL); kfree(req->buf); + req->buf = NULL; usb_ep_free_request(ep, req); }