Path: csiph.com!news.freedyn.net!aioe.org!bofh.it!news.nic.it!robomod From: Alexey Khoroshilov Newsgroups: linux.kernel Subject: Re: [PATCH] USB: whci-hcd: add more checks for dma mapping error Date: Sat, 26 Mar 2016 00:00:02 +0100 Message-ID: References: User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: robomod@news.nic.it List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Approved: robomod@news.nic.it Lines: 42 Organization: linux.* mail to news gateway X-Original-Cc: linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, ldv-project@linuxtesting.org X-Original-Date: Sat, 26 Mar 2016 01:56:52 +0300 X-Original-Message-ID: <56F5C234.3070606@ispras.ru> X-Original-References: <1458937421-18120-1-git-send-email-khoroshilov@ispras.ru> <56F5B59C.3050001@mleia.com> X-Original-Sender: linux-kernel-owner@vger.kernel.org Xref: csiph.com linux.kernel:1364871 On 26.03.2016 01:03, Vladimir Zapolskiy wrote: > On 25.03.2016 22:23, Alexey Khoroshilov wrote: >> Fixing checks for dma mapping error in qset_fill_page_list(), >> I have missed two similar problems in qset_add_urb_sg() and >> in qset_add_urb_sg_linearize(). >> >> Found by Linux Driver Verification project (linuxtesting.org). >> >> Signed-off-by: Alexey Khoroshilov >> --- >> drivers/usb/host/whci/qset.c | 6 +++++- >> 1 file changed, 5 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/usb/host/whci/qset.c b/drivers/usb/host/whci/qset.c >> index 1a8e960d073b..a8e9b618e643 100644 >> --- a/drivers/usb/host/whci/qset.c >> +++ b/drivers/usb/host/whci/qset.c >> @@ -535,9 +535,11 @@ static int qset_add_urb_sg(struct whc *whc, struct whc_qset *qset, struct urb *u >> list_for_each_entry(std, &qset->stds, list_node) { >> if (std->ntds_remaining == -1) { >> pl_len = std->num_pointers * sizeof(struct whc_page_list_entry); >> - std->ntds_remaining = ntds--; >> std->dma_addr = dma_map_single(whc->wusbhc.dev, std->pl_virt, >> pl_len, DMA_TO_DEVICE); >> + if (dma_mapping_error(whc->wusbhc.dev, std->dma_addr)) >> + return -EFAULT; > > Resources are leaked on error path: > * std->pl_virt -- most probably, at least it is freed on error path above, > * dma mappings done in a loop before met error, > As far as I can see, it is not the case. If qset_add_urb_sg() returns error code, the caller (qset_add_urb()) invokes qset_free_stds() that performs all resource deallocations. As for the error path above, I consider it as a typical krealloc() pattern, since it does not frees memory allocated at previous iterations of the cycle. Thank you, Alexey