| Message ID | 20230405181854.42355-1-jonathanh@nvidia.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 5629d31955297ca47b9283c64fff70f2f34aa528 |
| Headers | show |
| Series | [1/2] usb: gadget: tegra-xudc: Fix crash in vbus_draw | expand |
On Wed, Apr 05, 2023 at 07:18:53PM +0100, Jon Hunter wrote: > Commit ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") > populated the vbus_draw callback for the Tegra XUDC driver. The function > tegra_xudc_gadget_vbus_draw(), that was added by this commit, assumes > that the pointer 'curr_usbphy' has been initialised, which is not always > the case because this is only initialised when the USB role is updated. > Fix this crash, by checking that the 'curr_usbphy' is valid before > dereferencing. > > Fixes: ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > --- > drivers/usb/gadget/udc/tegra-xudc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c > index 2b71b33725f1..5bccd64847ff 100644 > --- a/drivers/usb/gadget/udc/tegra-xudc.c > +++ b/drivers/usb/gadget/udc/tegra-xudc.c > @@ -2167,7 +2167,7 @@ static int tegra_xudc_gadget_vbus_draw(struct usb_gadget *gadget, > > dev_dbg(xudc->dev, "%s: %u mA\n", __func__, m_a); > > - if (xudc->curr_usbphy->chg_type == SDP_TYPE) > + if (xudc->curr_usbphy && xudc->curr_usbphy->chg_type == SDP_TYPE) > ret = usb_phy_set_power(xudc->curr_usbphy, m_a); > > return ret; Looking at tegra_xudc_probe(), that calls tegra_xudc_update_data_role() for all PHYs, so shouldn't that be enough to get curr_usbphy set? Or is there perhaps a race between ->vbus_draw() and the data role update? Is ->vbus_draw() perhaps called as part of usb_add_gadget_udc()? Should we reorder those to make sure the role is properly updated before the gadget is registered? Thierry
On 06/04/2023 09:05, Thierry Reding wrote: > On Wed, Apr 05, 2023 at 07:18:53PM +0100, Jon Hunter wrote: >> Commit ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") >> populated the vbus_draw callback for the Tegra XUDC driver. The function >> tegra_xudc_gadget_vbus_draw(), that was added by this commit, assumes >> that the pointer 'curr_usbphy' has been initialised, which is not always >> the case because this is only initialised when the USB role is updated. >> Fix this crash, by checking that the 'curr_usbphy' is valid before >> dereferencing. >> >> Fixes: ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") >> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> >> --- >> drivers/usb/gadget/udc/tegra-xudc.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c >> index 2b71b33725f1..5bccd64847ff 100644 >> --- a/drivers/usb/gadget/udc/tegra-xudc.c >> +++ b/drivers/usb/gadget/udc/tegra-xudc.c >> @@ -2167,7 +2167,7 @@ static int tegra_xudc_gadget_vbus_draw(struct usb_gadget *gadget, >> >> dev_dbg(xudc->dev, "%s: %u mA\n", __func__, m_a); >> >> - if (xudc->curr_usbphy->chg_type == SDP_TYPE) >> + if (xudc->curr_usbphy && xudc->curr_usbphy->chg_type == SDP_TYPE) >> ret = usb_phy_set_power(xudc->curr_usbphy, m_a); >> >> return ret; > > Looking at tegra_xudc_probe(), that calls tegra_xudc_update_data_role() > for all PHYs, so shouldn't that be enough to get curr_usbphy set? Or is > there perhaps a race between ->vbus_draw() and the data role update? Is > ->vbus_draw() perhaps called as part of usb_add_gadget_udc()? Should we > reorder those to make sure the role is properly updated before the > gadget is registered? Yes it does call it, but it still does not set the curr_usbphy. If you look at the function it may not set it. In the backtrace I saw, which was happening on reboot, it was in the unregister of the gadget ... [ 1102.047896] Call trace: [ 1102.050402] 0xffffde9fd18c0878 [ 1102.053602] usb_gadget_vbus_draw+0x28/0x50 [ 1102.057879] composite_disconnect+0x1c/0x40 [libcomposite] [ 1102.063509] usb_get_function_instance+0x1808/0x27b0 [libcomposite] [ 1102.069935] usb_gadget_disconnect+0x64/0xa0 [ 1102.074304] usb_gadget_remove_driver+0x2c/0xc0 [ 1102.078942] usb_gadget_unregister_driver+0x70/0xf0 [ 1102.083927] usb_get_function_instance+0x2774/0x27b0 [libcomposite] [ 1102.090339] unregister_gadget_item+0x280/0x470 [libcomposite] [ 1102.096314] configfs_write_iter+0xc4/0x120 [ 1102.100609] new_sync_write+0xe8/0x190 [ 1102.104461] vfs_write+0x234/0x380 [ 1102.107938] ksys_write+0x6c/0x100 [ 1102.111417] __arm64_sys_write+0x1c/0x30 [ 1102.115427] invoke_syscall.constprop.0+0x4c/0xe0 [ 1102.120245] do_el0_svc+0x50/0x150 [ 1102.123723] el0_svc+0x28/0xc0 [ 1102.126854] el0t_64_sync_handler+0xb0/0xc0 [ 1102.131138] el0t_64_sync+0x1a0/0x1a4 [ 1102.134889] Code: 910003fd a90153f3 f94ce413 f100027f (b9409a60) [ 1102.141139] ---[ end trace cdf6612bd43fcbf2 ]--- Jon
On Thu, Apr 06, 2023 at 10:35:15AM +0100, Jon Hunter wrote: > > On 06/04/2023 09:05, Thierry Reding wrote: > > On Wed, Apr 05, 2023 at 07:18:53PM +0100, Jon Hunter wrote: > > > Commit ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") > > > populated the vbus_draw callback for the Tegra XUDC driver. The function > > > tegra_xudc_gadget_vbus_draw(), that was added by this commit, assumes > > > that the pointer 'curr_usbphy' has been initialised, which is not always > > > the case because this is only initialised when the USB role is updated. > > > Fix this crash, by checking that the 'curr_usbphy' is valid before > > > dereferencing. > > > > > > Fixes: ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") > > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > > > --- > > > drivers/usb/gadget/udc/tegra-xudc.c | 2 +- > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c > > > index 2b71b33725f1..5bccd64847ff 100644 > > > --- a/drivers/usb/gadget/udc/tegra-xudc.c > > > +++ b/drivers/usb/gadget/udc/tegra-xudc.c > > > @@ -2167,7 +2167,7 @@ static int tegra_xudc_gadget_vbus_draw(struct usb_gadget *gadget, > > > dev_dbg(xudc->dev, "%s: %u mA\n", __func__, m_a); > > > - if (xudc->curr_usbphy->chg_type == SDP_TYPE) > > > + if (xudc->curr_usbphy && xudc->curr_usbphy->chg_type == SDP_TYPE) > > > ret = usb_phy_set_power(xudc->curr_usbphy, m_a); > > > return ret; > > > > Looking at tegra_xudc_probe(), that calls tegra_xudc_update_data_role() > > for all PHYs, so shouldn't that be enough to get curr_usbphy set? Or is > > there perhaps a race between ->vbus_draw() and the data role update? Is > > ->vbus_draw() perhaps called as part of usb_add_gadget_udc()? Should we > > reorder those to make sure the role is properly updated before the > > gadget is registered? > > Yes it does call it, but it still does not set the curr_usbphy. If you look > at the function it may not set it. > > In the backtrace I saw, which was happening on reboot, it was in the > unregister of the gadget ... > > [ 1102.047896] Call trace: > [ 1102.050402] 0xffffde9fd18c0878 > [ 1102.053602] usb_gadget_vbus_draw+0x28/0x50 > [ 1102.057879] composite_disconnect+0x1c/0x40 [libcomposite] > [ 1102.063509] usb_get_function_instance+0x1808/0x27b0 [libcomposite] > [ 1102.069935] usb_gadget_disconnect+0x64/0xa0 > [ 1102.074304] usb_gadget_remove_driver+0x2c/0xc0 > [ 1102.078942] usb_gadget_unregister_driver+0x70/0xf0 > [ 1102.083927] usb_get_function_instance+0x2774/0x27b0 [libcomposite] > [ 1102.090339] unregister_gadget_item+0x280/0x470 [libcomposite] > [ 1102.096314] configfs_write_iter+0xc4/0x120 > [ 1102.100609] new_sync_write+0xe8/0x190 > [ 1102.104461] vfs_write+0x234/0x380 > [ 1102.107938] ksys_write+0x6c/0x100 > [ 1102.111417] __arm64_sys_write+0x1c/0x30 > [ 1102.115427] invoke_syscall.constprop.0+0x4c/0xe0 > [ 1102.120245] do_el0_svc+0x50/0x150 > [ 1102.123723] el0_svc+0x28/0xc0 > [ 1102.126854] el0t_64_sync_handler+0xb0/0xc0 > [ 1102.131138] el0t_64_sync+0x1a0/0x1a4 > [ 1102.134889] Code: 910003fd a90153f3 f94ce413 f100027f (b9409a60) > [ 1102.141139] ---[ end trace cdf6612bd43fcbf2 ]--- Alright. There are a lot of cases where we can run into this and it all looks a little complicated, so I think it would be good to unwind this at some point. But I can't think of an easy way to do that, so for a fix this looks good: Reviewed-by: Thierry Reding <treding@nvidia.com>
Hi Greg, On 06/04/2023 13:00, Thierry Reding wrote: > On Thu, Apr 06, 2023 at 10:35:15AM +0100, Jon Hunter wrote: >> >> On 06/04/2023 09:05, Thierry Reding wrote: >>> On Wed, Apr 05, 2023 at 07:18:53PM +0100, Jon Hunter wrote: >>>> Commit ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") >>>> populated the vbus_draw callback for the Tegra XUDC driver. The function >>>> tegra_xudc_gadget_vbus_draw(), that was added by this commit, assumes >>>> that the pointer 'curr_usbphy' has been initialised, which is not always >>>> the case because this is only initialised when the USB role is updated. >>>> Fix this crash, by checking that the 'curr_usbphy' is valid before >>>> dereferencing. >>>> >>>> Fixes: ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") >>>> Signed-off-by: Jon Hunter <jonathanh@nvidia.com> >>>> --- >>>> drivers/usb/gadget/udc/tegra-xudc.c | 2 +- >>>> 1 file changed, 1 insertion(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c >>>> index 2b71b33725f1..5bccd64847ff 100644 >>>> --- a/drivers/usb/gadget/udc/tegra-xudc.c >>>> +++ b/drivers/usb/gadget/udc/tegra-xudc.c >>>> @@ -2167,7 +2167,7 @@ static int tegra_xudc_gadget_vbus_draw(struct usb_gadget *gadget, >>>> dev_dbg(xudc->dev, "%s: %u mA\n", __func__, m_a); >>>> - if (xudc->curr_usbphy->chg_type == SDP_TYPE) >>>> + if (xudc->curr_usbphy && xudc->curr_usbphy->chg_type == SDP_TYPE) >>>> ret = usb_phy_set_power(xudc->curr_usbphy, m_a); >>>> return ret; >>> >>> Looking at tegra_xudc_probe(), that calls tegra_xudc_update_data_role() >>> for all PHYs, so shouldn't that be enough to get curr_usbphy set? Or is >>> there perhaps a race between ->vbus_draw() and the data role update? Is >>> ->vbus_draw() perhaps called as part of usb_add_gadget_udc()? Should we >>> reorder those to make sure the role is properly updated before the >>> gadget is registered? >> >> Yes it does call it, but it still does not set the curr_usbphy. If you look >> at the function it may not set it. >> >> In the backtrace I saw, which was happening on reboot, it was in the >> unregister of the gadget ... >> >> [ 1102.047896] Call trace: >> [ 1102.050402] 0xffffde9fd18c0878 >> [ 1102.053602] usb_gadget_vbus_draw+0x28/0x50 >> [ 1102.057879] composite_disconnect+0x1c/0x40 [libcomposite] >> [ 1102.063509] usb_get_function_instance+0x1808/0x27b0 [libcomposite] >> [ 1102.069935] usb_gadget_disconnect+0x64/0xa0 >> [ 1102.074304] usb_gadget_remove_driver+0x2c/0xc0 >> [ 1102.078942] usb_gadget_unregister_driver+0x70/0xf0 >> [ 1102.083927] usb_get_function_instance+0x2774/0x27b0 [libcomposite] >> [ 1102.090339] unregister_gadget_item+0x280/0x470 [libcomposite] >> [ 1102.096314] configfs_write_iter+0xc4/0x120 >> [ 1102.100609] new_sync_write+0xe8/0x190 >> [ 1102.104461] vfs_write+0x234/0x380 >> [ 1102.107938] ksys_write+0x6c/0x100 >> [ 1102.111417] __arm64_sys_write+0x1c/0x30 >> [ 1102.115427] invoke_syscall.constprop.0+0x4c/0xe0 >> [ 1102.120245] do_el0_svc+0x50/0x150 >> [ 1102.123723] el0_svc+0x28/0xc0 >> [ 1102.126854] el0t_64_sync_handler+0xb0/0xc0 >> [ 1102.131138] el0t_64_sync+0x1a0/0x1a4 >> [ 1102.134889] Code: 910003fd a90153f3 f94ce413 f100027f (b9409a60) >> [ 1102.141139] ---[ end trace cdf6612bd43fcbf2 ]--- > > Alright. There are a lot of cases where we can run into this and it all > looks a little complicated, so I think it would be good to unwind this > at some point. But I can't think of an easy way to do that, so for a fix > this looks good: > > Reviewed-by: Thierry Reding <treding@nvidia.com> OK for pick this up v6.4? Thanks Jon
On Wed, Apr 19, 2023 at 10:53:42PM +0100, Jon Hunter wrote: > Hi Greg, > > On 06/04/2023 13:00, Thierry Reding wrote: > > On Thu, Apr 06, 2023 at 10:35:15AM +0100, Jon Hunter wrote: > > > > > > On 06/04/2023 09:05, Thierry Reding wrote: > > > > On Wed, Apr 05, 2023 at 07:18:53PM +0100, Jon Hunter wrote: > > > > > Commit ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") > > > > > populated the vbus_draw callback for the Tegra XUDC driver. The function > > > > > tegra_xudc_gadget_vbus_draw(), that was added by this commit, assumes > > > > > that the pointer 'curr_usbphy' has been initialised, which is not always > > > > > the case because this is only initialised when the USB role is updated. > > > > > Fix this crash, by checking that the 'curr_usbphy' is valid before > > > > > dereferencing. > > > > > > > > > > Fixes: ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") > > > > > Signed-off-by: Jon Hunter <jonathanh@nvidia.com> > > > > > --- > > > > > drivers/usb/gadget/udc/tegra-xudc.c | 2 +- > > > > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > > > > > > > diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c > > > > > index 2b71b33725f1..5bccd64847ff 100644 > > > > > --- a/drivers/usb/gadget/udc/tegra-xudc.c > > > > > +++ b/drivers/usb/gadget/udc/tegra-xudc.c > > > > > @@ -2167,7 +2167,7 @@ static int tegra_xudc_gadget_vbus_draw(struct usb_gadget *gadget, > > > > > dev_dbg(xudc->dev, "%s: %u mA\n", __func__, m_a); > > > > > - if (xudc->curr_usbphy->chg_type == SDP_TYPE) > > > > > + if (xudc->curr_usbphy && xudc->curr_usbphy->chg_type == SDP_TYPE) > > > > > ret = usb_phy_set_power(xudc->curr_usbphy, m_a); > > > > > return ret; > > > > > > > > Looking at tegra_xudc_probe(), that calls tegra_xudc_update_data_role() > > > > for all PHYs, so shouldn't that be enough to get curr_usbphy set? Or is > > > > there perhaps a race between ->vbus_draw() and the data role update? Is > > > > ->vbus_draw() perhaps called as part of usb_add_gadget_udc()? Should we > > > > reorder those to make sure the role is properly updated before the > > > > gadget is registered? > > > > > > Yes it does call it, but it still does not set the curr_usbphy. If you look > > > at the function it may not set it. > > > > > > In the backtrace I saw, which was happening on reboot, it was in the > > > unregister of the gadget ... > > > > > > [ 1102.047896] Call trace: > > > [ 1102.050402] 0xffffde9fd18c0878 > > > [ 1102.053602] usb_gadget_vbus_draw+0x28/0x50 > > > [ 1102.057879] composite_disconnect+0x1c/0x40 [libcomposite] > > > [ 1102.063509] usb_get_function_instance+0x1808/0x27b0 [libcomposite] > > > [ 1102.069935] usb_gadget_disconnect+0x64/0xa0 > > > [ 1102.074304] usb_gadget_remove_driver+0x2c/0xc0 > > > [ 1102.078942] usb_gadget_unregister_driver+0x70/0xf0 > > > [ 1102.083927] usb_get_function_instance+0x2774/0x27b0 [libcomposite] > > > [ 1102.090339] unregister_gadget_item+0x280/0x470 [libcomposite] > > > [ 1102.096314] configfs_write_iter+0xc4/0x120 > > > [ 1102.100609] new_sync_write+0xe8/0x190 > > > [ 1102.104461] vfs_write+0x234/0x380 > > > [ 1102.107938] ksys_write+0x6c/0x100 > > > [ 1102.111417] __arm64_sys_write+0x1c/0x30 > > > [ 1102.115427] invoke_syscall.constprop.0+0x4c/0xe0 > > > [ 1102.120245] do_el0_svc+0x50/0x150 > > > [ 1102.123723] el0_svc+0x28/0xc0 > > > [ 1102.126854] el0t_64_sync_handler+0xb0/0xc0 > > > [ 1102.131138] el0t_64_sync+0x1a0/0x1a4 > > > [ 1102.134889] Code: 910003fd a90153f3 f94ce413 f100027f (b9409a60) > > > [ 1102.141139] ---[ end trace cdf6612bd43fcbf2 ]--- > > > > Alright. There are a lot of cases where we can run into this and it all > > looks a little complicated, so I think it would be good to unwind this > > at some point. But I can't think of an easy way to do that, so for a fix > > this looks good: > > > > Reviewed-by: Thierry Reding <treding@nvidia.com> > > OK for pick this up v6.4? It's in my queue, which is big, I'm at a conference this week but will try to get to it today on the train ride... greg k-h
diff --git a/drivers/usb/gadget/udc/tegra-xudc.c b/drivers/usb/gadget/udc/tegra-xudc.c index 2b71b33725f1..5bccd64847ff 100644 --- a/drivers/usb/gadget/udc/tegra-xudc.c +++ b/drivers/usb/gadget/udc/tegra-xudc.c @@ -2167,7 +2167,7 @@ static int tegra_xudc_gadget_vbus_draw(struct usb_gadget *gadget, dev_dbg(xudc->dev, "%s: %u mA\n", __func__, m_a); - if (xudc->curr_usbphy->chg_type == SDP_TYPE) + if (xudc->curr_usbphy && xudc->curr_usbphy->chg_type == SDP_TYPE) ret = usb_phy_set_power(xudc->curr_usbphy, m_a); return ret;
Commit ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") populated the vbus_draw callback for the Tegra XUDC driver. The function tegra_xudc_gadget_vbus_draw(), that was added by this commit, assumes that the pointer 'curr_usbphy' has been initialised, which is not always the case because this is only initialised when the USB role is updated. Fix this crash, by checking that the 'curr_usbphy' is valid before dereferencing. Fixes: ac82b56bda5f ("usb: gadget: tegra-xudc: Add vbus_draw support") Signed-off-by: Jon Hunter <jonathanh@nvidia.com> --- drivers/usb/gadget/udc/tegra-xudc.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)