On 11/5/2024 4:21 PM, Bryan O'Donoghue wrote:
On 05/11/2024 08:54, 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.
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; cap = &caps[core->codecs_count++]; cap->codec = BIT(bit); cap->domain = VIDC_SESSION_TYPE_DEC; @@ -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; cap = &caps[core->codecs_count++]; cap->codec = BIT(bit); cap->domain = VIDC_SESSION_TYPE_ENC;
I don't see how codecs_count could be greater than the control, since you increment by one on each loop but >= is fine too I suppose.
Assume the payload from malicious firmware is packed like below HFI_PROPERTY_PARAM_CODEC_SUPPORTED HFI_PROPERTY_PARAM_CODEC_SUPPORTED HFI_PROPERTY_PARAM_CODEC_SUPPORTED ..... for 32 or more instances of above type
Regards, Vikash
Reviewed-by: Bryan O'Donoghue bryan.odonoghue@linaro.org