On Thu, Nov 07, 2024 at 01:47:20PM +0530, Vikash Garodia wrote:
On 11/5/2024 7:25 PM, Dmitry Baryshkov wrote:
On Tue, Nov 05, 2024 at 02:24:54PM +0530, Vikash Garodia wrote:
There is a possibility that init_codecs is invoked multiple times during manipulated payload from video firmware. In such case, if codecs_count can get incremented to value more than MAX_CODEC_NUM, there can be OOB access. Keep a check for max accessible memory before accessing it.
No. Please make sure that init_codecs() does a correct thing, so that core->codecs_count isn't incremented that much (or even better that init_codecs() doesn't do anything if it is executed second time).
init_codecs() parses the payload received from firmware and . I don't think we can control this part when we have something like this from a malicious firmware payload HFI_PROPERTY_PARAM_CODEC_SUPPORTED HFI_PROPERTY_PARAM_CODEC_SUPPORTED HFI_PROPERTY_PARAM_CODEC_SUPPORTED ... Limiting it to second iteration would restrict the functionality when property HFI_PROPERTY_PARAM_CODEC_SUPPORTED is sent for supported number of codecs.
If you can have a malicious firmware (which is owned and signed by Qualcomm / OEM), then you have to be careful and skip duplicates. So instead of just adding new cap to core->caps, you have to go through that array, check that you are not adding a duplicate (and report a [Firmware Bug] for duplicates), check that there is an empty slot, etc.
Just ignoring the "extra" entries is not enough.
Regards, Vikash
Cc: stable@vger.kernel.org Fixes: 1a73374a04e5 ("media: venus: hfi_parser: add common capability parser") Signed-off-by: Vikash Garodia quic_vgarodia@quicinc.com
drivers/media/platform/qcom/venus/hfi_parser.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/media/platform/qcom/venus/hfi_parser.c b/drivers/media/platform/qcom/venus/hfi_parser.c index 3df241dc3a118bcdeb2c28a6ffdb907b644d5653..27d0172294d5154f4839e8cef172f9a619dfa305 100644 --- a/drivers/media/platform/qcom/venus/hfi_parser.c +++ b/drivers/media/platform/qcom/venus/hfi_parser.c @@ -23,6 +23,8 @@ static void init_codecs(struct venus_core *core) return; for_each_set_bit(bit, &core->dec_codecs, MAX_CODEC_NUM) {
if (core->codecs_count >= MAX_CODEC_NUM)return;@@ -30,6 +32,8 @@ static void init_codecs(struct venus_core *core) } for_each_set_bit(bit, &core->enc_codecs, MAX_CODEC_NUM) {
if (core->codecs_count >= MAX_CODEC_NUM)return;-- 2.34.1