Messages in this thread | | | Date | Thu, 8 Feb 2024 19:59:20 +0530 | Subject | Re: [PATCH v3] soc: qcom: mdt_loader: Add Upperbounds check for program header access | From | Mukesh Ojha <> |
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On 2/8/2024 6:05 PM, Auditya Bhattaram wrote: > hash_index is evaluated by looping phdrs till QCOM_MDT_TYPE_HASH > is found. Add an upperbound check to phdrs to access within elf size. > > Fixes: 64fb5eb87d58 ("soc: qcom: mdt_loader: Allow hash to reside in any segment") > Cc: <stable@vger.kernel.org> > Signed-off-by: Auditya Bhattaram <quic_audityab@quicinc.com> > --- > Changes in v3: > - Corrected wrong patch versioning in the Subject. > - Added error prints for Invalid access. > Link to v2 https://lore.kernel.org/linux-arm-msm/9773d189-c896-d5c5-804c-e086c24987b4@quicinc.com/T/#t > Link to v1 https://lore.kernel.org/linux-arm-msm/5d7a3b97-d840-4863-91a0-32c1d8e7532f@linaro.org/T/#t > --- > drivers/soc/qcom/mdt_loader.c | 5 +++++ > 1 file changed, 5 insertions(+) > > diff --git a/drivers/soc/qcom/mdt_loader.c b/drivers/soc/qcom/mdt_loader.c > index 6f177e46fa0f..61e2377cc5c3 100644 > --- a/drivers/soc/qcom/mdt_loader.c > +++ b/drivers/soc/qcom/mdt_loader.c > @@ -145,6 +145,11 @@ void *qcom_mdt_read_metadata(const struct firmware *fw, size_t *data_len, > if (phdrs[0].p_type == PT_LOAD) > return ERR_PTR(-EINVAL); > > + if (((size_t)(phdrs + ehdr->e_phnum)) > ((size_t)ehdr + fw->size)) {
This change is valid only if somehow, ehdr->e_phnum gets corrupted or changed via some engineering means and results in out-of-bounds access.
Acked-by: Mukesh Ojha <quic_mojha@quicinc.com>
> + dev_err(dev, "Invalid phdrs access: %s\n", fw_name);
Should it print ehdr->e_phnum as well to be more valid?
-Mukesh
> + return ERR_PTR(-EINVAL); > + } > + > for (i = 1; i < ehdr->e_phnum; i++) { > if ((phdrs[i].p_flags & QCOM_MDT_TYPE_MASK) == QCOM_MDT_TYPE_HASH) { > hash_segment = i; > -- > 2.17.1 > >
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