Messages in this thread | ![/](/images/icornerl.gif) | | Date | Mon, 29 Jan 2024 16:18:36 +0530 | Subject | Re: [RFC PATCH] rpmsg: glink: Add bounds check on tx path | From | Deepak Kumar Singh <> |
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On 1/13/2024 5:55 AM, Michal Koutný wrote: > Add bounds check on values read from shared memory in the tx path. In > cases where the VM is misbehaving, the transport should exit and print a > warning when bogus values may cause out of bounds to be read. > > Link: https://git.codelinaro.org/clo/la/kernel/msm-5.10/-/commit/32d9c3a2f2b6a4d1fc48d6871194f3faf3184e8b > Suggested-by: Chris Lew <quic_clew@quicinc.com> > Suggested-by: Sarannya S <quic_sarannya@quicinc.com> > Signed-off-by: Michal Koutný <mkoutny@suse.com> > --- > drivers/rpmsg/qcom_glink_smem.c | 9 +++++++++ > 1 file changed, 9 insertions(+) > > Why RFC? The patch is adopted from the link above. It would be good to > asses whether such conditions can also happen with rpmsg glink. > (And if so, whether the zeroed values are the best correction.) > Hi Michal,
There is already a patch posted for similar problem - https://lore.kernel.org/all/20231201110631.669085-1-quic_deesin@quicinc.com/
> diff --git a/drivers/rpmsg/qcom_glink_smem.c b/drivers/rpmsg/qcom_glink_smem.c > index 7a982c60a8dd..3e786e590c03 100644 > --- a/drivers/rpmsg/qcom_glink_smem.c > +++ b/drivers/rpmsg/qcom_glink_smem.c > @@ -146,6 +146,11 @@ static size_t glink_smem_tx_avail(struct qcom_glink_pipe *np) > else > avail -= FIFO_FULL_RESERVE + TX_BLOCKED_CMD_RESERVE; > > + if (avail > pipe->native.length) { > + pr_warn_once("%s: avail clamped\n", __func__); > + avail = 0; > + } > + > return avail; > } > > @@ -177,6 +182,10 @@ static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe, > unsigned int head; > > head = le32_to_cpu(*pipe->head); > + if (head > pipe->native.length) { > + pr_warn_once("%s: head overflow\n", __func__); > + return; > + } > > head = glink_smem_tx_write_one(pipe, head, hdr, hlen); > head = glink_smem_tx_write_one(pipe, head, data, dlen);
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