From 499350865387f8b8c40a9e9453a9a7eb3cec5dc4 Mon Sep 17 00:00:00 2001 From: Fabio Estevam Date: Thu, 18 Jan 2018 00:22:45 -0200 Subject: usb: phy: mxs: Fix NULL pointer dereference on i.MX23/28 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") Cc: # v4.15 Reviewed-by: Li Jun Acked-by: Peter Chen Signed-off-by: Fabio Estevam Signed-off-by: Felipe Balbi --- drivers/usb/phy/phy-mxs-usb.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/usb/phy/phy-mxs-usb.c') diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c index da031c45395a..fbec863350f6 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; -- cgit v1.2.3