On Fri, Mar 24, 2023 at 10:13:04AM -0600, Jeffrey Hugo wrote:

If the value read from the CHDBOFF and ERDBOFF registers is outside the range of the MHI register space then an invalid address might be computed which later causes a kernel panic. Range check the read value to prevent a crash due to bad data from the device.

Fixes: 6cd330ae76ff ("bus: mhi: core: Add support for ringing channel/event ring doorbells") Cc: stable@vger.kernel.org Signed-off-by: Jeffrey Hugo quic_jhugo@quicinc.com

Reviewed-by: Manivannan Sadhasivam mani@kernel.org

Thanks, Mani

Reviewed-by: Pranjal Ramajor Asha Kanojiya quic_pkanojiy@quicinc.com

v2: -CC stable -Use ERANGE for the error code

drivers/bus/mhi/host/init.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)

diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c index 3d779ee..b46a082 100644 --- a/drivers/bus/mhi/host/init.c +++ b/drivers/bus/mhi/host/init.c @@ -516,6 +516,12 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl) return -EIO; }

• if (val >= mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB)) {

• dev_err(dev, "CHDB offset: 0x%x is out of range: 0x%zx\n",
  

• 	val, mhi_cntrl->reg_len - (8 * MHI_DEV_WAKE_DB));
  

• return -ERANGE;
  

• }
• /* Setup wake db */ mhi_cntrl->wake_db = base + val + (8 * MHI_DEV_WAKE_DB); mhi_cntrl->wake_set = false;

@@ -532,6 +538,12 @@ int mhi_init_mmio(struct mhi_controller *mhi_cntrl) return -EIO; }

• if (val >= mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings)) {

• dev_err(dev, "ERDB offset: 0x%x is out of range: 0x%zx\n",
  

• 	val, mhi_cntrl->reg_len - (8 * mhi_cntrl->total_ev_rings));
  

• return -ERANGE;
  

• }
• /* Setup event db address for each ev_ring */ mhi_event = mhi_cntrl->mhi_event; for (i = 0; i < mhi_cntrl->total_ev_rings; i++, val += 8, mhi_event++) {

-- 2.7.4