On 3/24/2023 4:34 AM, Manivannan Sadhasivam wrote:
On Fri, Mar 17, 2023 at 09:14:19AM -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")
Please CC stable list.
The stable folks have been automatically picking up everything with a
fixes tag for years. CCing the stable list does not seem to do anything
unless the patch needs specific backporting adjustments.
Do you still want an explicit CC?
Signed-off-by: Jeffrey Hugo <quic_jhugo@xxxxxxxxxxx>
Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@xxxxxxxxxxx>
---
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..ae8ebcfb 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 -EINVAL;
Isn't -ERANGE a better errno here and also in other places of the driver?
I suppose that could work. This was modeled after the existing BHI (eg
BHIOFF) range checks. You want those updated in the same change or a
separate one?
Thanks,
Mani
+ }
+
/* 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 -EINVAL;
+ }
+
/* 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
