From mboxrd@z Thu Jan 1 00:00:00 1970 From: narmstrong@baylibre.com (Neil Armstrong) Date: Tue, 20 Mar 2018 17:16:41 +0100 Subject: [PATCH -next] drm/meson: Fix potential NULL dereference in meson_drv_bind_master() In-Reply-To: <4cad8099-dbb8-d12c-9ce8-b64688222bd7@baylibre.com> References: <1521555630-29284-1-git-send-email-weiyongjun1@huawei.com> <4cad8099-dbb8-d12c-9ce8-b64688222bd7@baylibre.com> Message-ID: <1772626e-c521-a072-76e4-64e3b4883f2e@baylibre.com> To: linus-amlogic@lists.infradead.org List-Id: linus-amlogic.lists.infradead.org On 20/03/2018 16:04, Neil Armstrong wrote: > On 20/03/2018 15:20, Wei Yongjun wrote: >> platform_get_resource_byname() may fail and return NULL, so we should >> better check it's return value to avoid a NULL pointer dereference >> a bit later in the code. >> >> This is detected by Coccinelle semantic patch. >> >> @@ >> expression pdev, res, n, t, e, e1, e2; >> @@ >> >> res = platform_get_resource_byname(pdev, t, n); >> + if (!res) >> + return -EINVAL; >> ... when != res == NULL >> e = devm_ioremap(e1, res->start, e2); >> >> Signed-off-by: Wei Yongjun >> --- >> drivers/gpu/drm/meson/meson_drv.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/gpu/drm/meson/meson_drv.c b/drivers/gpu/drm/meson/meson_drv.c >> index 3baceb7..32b1a6c 100644 >> --- a/drivers/gpu/drm/meson/meson_drv.c >> +++ b/drivers/gpu/drm/meson/meson_drv.c >> @@ -197,6 +197,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components) >> priv->io_base = regs; >> >> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "hhi"); >> + if (!res) >> + return -EINVAL; >> /* Simply ioremap since it may be a shared register zone */ >> regs = devm_ioremap(dev, res->start, resource_size(res)); >> if (!regs) { >> @@ -213,6 +215,8 @@ static int meson_drv_bind_master(struct device *dev, bool has_components) >> } >> >> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "dmc"); >> + if (!res) >> + return -EINVAL; >> /* Simply ioremap since it may be a shared register zone */ >> regs = devm_ioremap(dev, res->start, resource_size(res)); >> if (!regs) { >> >> >> _______________________________________________ >> linux-amlogic mailing list >> linux-amlogic at lists.infradead.org >> http://lists.infradead.org/mailman/listinfo/linux-amlogic >> > Thanks, > > Acked-by: Neil Armstrong > Applied to drm-misc-next