vhci_hub_control() accesses port_status array with out of bounds port value. Fix it to reference port_status[] only with a valid rhport value when invalid_rhport flag is true.
The invalid_rhport flag is set early on after detecting in port value is within the bounds or not. The following is used reproduce the problem and verify the fix: C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14ed8ab6400000 Reported-by: syzbot+bccc1fe10b70fadc7...@syzkaller.appspotmail.com Signed-off-by: Shuah Khan (Samsung OSG) <sh...@kernel.org> --- drivers/usb/usbip/vhci_hcd.c | 57 ++++++++++++++++++++++++++---------- 1 file changed, 42 insertions(+), 15 deletions(-) diff --git a/drivers/usb/usbip/vhci_hcd.c b/drivers/usb/usbip/vhci_hcd.c index d11f3f8dad40..1e592ec94ba4 100644 --- a/drivers/usb/usbip/vhci_hcd.c +++ b/drivers/usb/usbip/vhci_hcd.c @@ -318,8 +318,9 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, struct vhci_hcd *vhci_hcd; struct vhci *vhci; int retval = 0; - int rhport; + int rhport = -1; unsigned long flags; + bool invalid_rhport = false; u32 prev_port_status[VHCI_HC_PORTS]; @@ -334,9 +335,19 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, usbip_dbg_vhci_rh("typeReq %x wValue %x wIndex %x\n", typeReq, wValue, wIndex); - if (wIndex > VHCI_HC_PORTS) - pr_err("invalid port number %d\n", wIndex); - rhport = wIndex - 1; + /* + * wIndex can be 0 for some request types (typeReq). rhport is + * in valid range when wIndex >= 1 and < VHCI_HC_PORTS. + * + * Reference port_status[] only with valid rhport when + * invalid_rhport is false. + */ + if (wIndex < 1 || wIndex > VHCI_HC_PORTS) { + invalid_rhport = true; + if (wIndex > VHCI_HC_PORTS) + pr_err("invalid port number %d\n", wIndex); + } else + rhport = wIndex - 1; vhci_hcd = hcd_to_vhci_hcd(hcd); vhci = vhci_hcd->vhci; @@ -345,8 +356,9 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, /* store old status and compare now and old later */ if (usbip_dbg_flag_vhci_rh) { - memcpy(prev_port_status, vhci_hcd->port_status, - sizeof(prev_port_status)); + if (!invalid_rhport) + memcpy(prev_port_status, vhci_hcd->port_status, + sizeof(prev_port_status)); } switch (typeReq) { @@ -354,8 +366,10 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, usbip_dbg_vhci_rh(" ClearHubFeature\n"); break; case ClearPortFeature: - if (rhport < 0) + if (invalid_rhport) { + pr_err("invalid port number %d\n", wIndex); goto error; + } switch (wValue) { case USB_PORT_FEAT_SUSPEND: if (hcd->speed == HCD_USB3) { @@ -415,9 +429,10 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, break; case GetPortStatus: usbip_dbg_vhci_rh(" GetPortStatus port %x\n", wIndex); - if (wIndex < 1) { + if (invalid_rhport) { pr_err("invalid port number %d\n", wIndex); retval = -EPIPE; + goto error; } /* we do not care about resume. */ @@ -513,16 +528,20 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, goto error; } - if (rhport < 0) + if (invalid_rhport) { + pr_err("invalid port number %d\n", wIndex); goto error; + } vhci_hcd->port_status[rhport] |= USB_PORT_STAT_SUSPEND; break; case USB_PORT_FEAT_POWER: usbip_dbg_vhci_rh( " SetPortFeature: USB_PORT_FEAT_POWER\n"); - if (rhport < 0) + if (invalid_rhport) { + pr_err("invalid port number %d\n", wIndex); goto error; + } if (hcd->speed == HCD_USB3) vhci_hcd->port_status[rhport] |= USB_SS_PORT_STAT_POWER; else @@ -531,8 +550,10 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, case USB_PORT_FEAT_BH_PORT_RESET: usbip_dbg_vhci_rh( " SetPortFeature: USB_PORT_FEAT_BH_PORT_RESET\n"); - if (rhport < 0) + if (invalid_rhport) { + pr_err("invalid port number %d\n", wIndex); goto error; + } /* Applicable only for USB3.0 hub */ if (hcd->speed != HCD_USB3) { pr_err("USB_PORT_FEAT_BH_PORT_RESET req not " @@ -543,8 +564,10 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, case USB_PORT_FEAT_RESET: usbip_dbg_vhci_rh( " SetPortFeature: USB_PORT_FEAT_RESET\n"); - if (rhport < 0) + if (invalid_rhport) { + pr_err("invalid port number %d\n", wIndex); goto error; + } /* if it's already enabled, disable */ if (hcd->speed == HCD_USB3) { vhci_hcd->port_status[rhport] = 0; @@ -565,8 +588,10 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, default: usbip_dbg_vhci_rh(" SetPortFeature: default %d\n", wValue); - if (rhport < 0) + if (invalid_rhport) { + pr_err("invalid port number %d\n", wIndex); goto error; + } if (hcd->speed == HCD_USB3) { if ((vhci_hcd->port_status[rhport] & USB_SS_PORT_STAT_POWER) != 0) { @@ -608,7 +633,7 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, if (usbip_dbg_flag_vhci_rh) { pr_debug("port %d\n", rhport); /* Only dump valid port status */ - if (rhport >= 0) { + if (!invalid_rhport) { dump_port_status_diff(prev_port_status[rhport], vhci_hcd->port_status[rhport], hcd->speed == HCD_USB3); @@ -618,8 +643,10 @@ static int vhci_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue, spin_unlock_irqrestore(&vhci->lock, flags); - if ((vhci_hcd->port_status[rhport] & PORT_C_MASK) != 0) + if (!invalid_rhport && + (vhci_hcd->port_status[rhport] & PORT_C_MASK) != 0) { usb_hcd_poll_rh_status(hcd); + } return retval; } -- 2.17.0
