From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4/uivpUwKlJnD5BkHLRm6L8RRgZZKtule4GKzDWpQTm2W/EPnJyhahc5oondbYjeRzwZLmc ARC-Seal: i=1; a=rsa-sha256; t=1524405370; cv=none; d=google.com; s=arc-20160816; b=JoARpNzwFj/Yj5tysEV7aRgg4vk2xKrftC0R/isAoE3Ul0E8+NQBsPxZ1AwA0A9CF9 zQlFI4HvHIS102EAhhThuiqLp2NpTteRsc5nFQlaCasGlasagS68oJ/iUJhYo+iYikAE gVKTFZZQdOzLOZUl2oAUHntpWY75efJVPDazuTfgqq2pXkZFwtIWdaQXJHjtY3wJV+sK 4FIEvohMnGsBeKcQZpsxbmQDgcoxM4lwFr0Bq4Ar1zkzXVkS/kYjiqN4j1kASY49gvSb WN0YvawoYfrMIHq6q0XNDbChtrjCoG0dS2r2b5qgh03M+P4Tt5nPoqrlvQySoRhuyltQ TpzA== 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=7dB69dvaTI7SGW2cgmdPXn51waSYnpoD90XMsz8zOGM=; b=y1OsBPbtAJnwzNXon2xSH6GuM7mI17plN6gkmWyjNqm5YjBNnS2DSAFwYuJueZCWeY 2T3goyq+opEw2z2QNZklRU8mS896STNs1oV1LvNnW2sMvGPbj7KTn55XhraSFI6S3gCX I5eihFUlGI02A1La8wVRkWXWJQAVefUglDds6IF9Fan3Zijzi3PT8Wo2pmwdJqol7qbX q9Uxvrf/OfMcWwMfzDxYdJjJDcOb6PwV1xIRNOIOSeHvR0HO2oFaOAGmkbaityxZGX8k ppnzq8QV+on5jf6dCN8uOXzWMM0gRvnODRAlQubCi/iTJqlvHbKnRUWVNpM4qrr6zmEi xC+A== 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 4.16 040/196] USB: gadget: f_midi: fixing a possible double-free in f_midi Date: Sun, 22 Apr 2018 15:51:00 +0200 Message-Id: <20180422135106.154436732@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180422135104.278511750@linuxfoundation.org> References: <20180422135104.278511750@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?1598454885662324670?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.16-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 @@ -404,7 +404,8 @@ 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 @@ -61,7 +61,9 @@ 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); }