> -----Original Message----- > From: Fabio Estevam [mailto:festevam@xxxxxxxxx] > Sent: Thursday, January 18, 2018 10:23 AM > To: balbi@xxxxxxxxxx > Cc: Jun Li <jun.li@xxxxxxx>; baolin.wang@xxxxxxxxxx; Peter Chen > <peter.chen@xxxxxxx>; linux-usb@xxxxxxxxxxxxxxx; Fabio Estevam > <fabio.estevam@xxxxxxx> > Subject: [PATCH v2] usb: phy: mxs: Fix NULL pointer dereference on i.MX23/28 > > From: Fabio Estevam <fabio.estevam@xxxxxxx> > > Commit e93650994a95 ("usb: phy: mxs: add usb charger type detection") causes > the following kernel hang on i.MX28: > > [ 2.207973] usbcore: registered new interface driver usb-storage > [ 2.235659] Unable to handle kernel NULL pointer dereference at virtual > address 00000188 > [ 2.244195] pgd = (ptrval) > [ 2.246994] [00000188] *pgd=00000000 > [ 2.250676] Internal error: Oops: 5 [#1] ARM > [ 2.254979] Modules linked in: > [ 2.258089] CPU: 0 PID: 1 Comm: swapper Not tainted 4.15.0-rc8-next- > 20180117-00002-g75d5f21 #7 > [ 2.266724] Hardware name: Freescale MXS (Device Tree) > [ 2.271921] PC is at regmap_read+0x0/0x5c > [ 2.275977] LR is at mxs_phy_charger_detect+0x34/0x1dc > > mxs_phy_charger_detect() makes accesses to the anatop registers via regmap, > however i.MX23/28 do not have such registers, which causes a NULL pointer > dereference. > > Fix the issue by doing a NULL check on the 'regmap' pointer. > > Fixes: e93650994a95 ("usb: phy: mxs: add usb charger type detection") > Signed-off-by: Fabio Estevam <fabio.estevam@xxxxxxx> Reviewed-by: Li Jun <jun.li@xxxxxxx> > --- > Changes since v1: > - Perform a NULL check on regmap (Jun Li) > > drivers/usb/phy/phy-mxs-usb.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c > index da031c4..4e2eb9d 100644 > --- a/drivers/usb/phy/phy-mxs-usb.c > +++ b/drivers/usb/phy/phy-mxs-usb.c > @@ -602,6 +602,9 @@ static enum usb_charger_type > mxs_phy_charger_detect(struct usb_phy *phy) > void __iomem *base = phy->io_priv; > enum usb_charger_type chgr_type = UNKNOWN_TYPE; > > + if (!regmap) > + return UNKNOWN_TYPE; > + > if (mxs_charger_data_contact_detect(mxs_phy)) > return chgr_type; > > -- > 2.7.4 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
