diff mbox series

[v2,3/4] venus: hfi: add checks to handle capabilities from firmware

Message ID 1691634304-2158-4-git-send-email-quic_vgarodia@quicinc.com
State Accepted
Commit 8d0b89398b7ebc52103e055bf36b60b045f5258f
Headers show
Series Venus driver fixes to avoid possible OOB accesses | expand

Commit Message

Vikash Garodia Aug. 10, 2023, 2:25 a.m. UTC
The hfi parser, parses the capabilities received from venus firmware and
copies them to core capabilities. Consider below api, for example,
fill_caps - In this api, caps in core structure gets updated with the
number of capabilities received in firmware data payload. If the same api
is called multiple times, there is a possibility of copying beyond the max
allocated size in core caps.
Similar possibilities in fill_raw_fmts and fill_profile_level functions.

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 | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Vikash Garodia Aug. 11, 2023, 4:10 p.m. UTC | #1
On 8/11/2023 4:09 PM, Bryan O'Donoghue wrote:
> On 11/08/2023 09:51, Vikash Garodia wrote:
>>
>> On 8/11/2023 2:11 PM, Bryan O'Donoghue wrote:
>>> On 11/08/2023 06:54, Vikash Garodia wrote:
>>>> The case is all about rogue firmware. If there is a need to fill the same cap
>>>> again, that itself indicates that the payload from firmware is not correct. In
>>>> such cases, the old as well as new cap data are not reliable. Though the
>>>> authenticity of the data cannot be ensured, the check would avoid any OOB
>>>> during
>>>> such rogue firmware case.
>>>
>>> Then why favour the old cap report over the new ?
>>
>> When the driver hits the case for OOB, thats when it knows that something has
>> gone wrong. Keeping old or new, both are invalid values in such case, nothing to
>> favor any value.
>>
>> Regards,
>> Vikash
> 
> Is this hypothetical or a real bug you are actually working to mitigate ?

These are theoretical bugs, not reported during any video usecase so far. At the
same time, these are quite possible when the packets from firmware goes
different than expected.

> ---
> bod
diff mbox series

Patch

diff --git a/drivers/media/platform/qcom/venus/hfi_parser.c b/drivers/media/platform/qcom/venus/hfi_parser.c
index 6cf74b2..9d6ba22 100644
--- a/drivers/media/platform/qcom/venus/hfi_parser.c
+++ b/drivers/media/platform/qcom/venus/hfi_parser.c
@@ -86,6 +86,9 @@  static void fill_profile_level(struct hfi_plat_caps *cap, const void *data,
 {
 	const struct hfi_profile_level *pl = data;
 
+	if (cap->num_pl + num >= HFI_MAX_PROFILE_COUNT)
+		return;
+
 	memcpy(&cap->pl[cap->num_pl], pl, num * sizeof(*pl));
 	cap->num_pl += num;
 }
@@ -111,6 +114,9 @@  fill_caps(struct hfi_plat_caps *cap, const void *data, unsigned int num)
 {
 	const struct hfi_capability *caps = data;
 
+	if (cap->num_caps + num >= MAX_CAP_ENTRIES)
+		return;
+
 	memcpy(&cap->caps[cap->num_caps], caps, num * sizeof(*caps));
 	cap->num_caps += num;
 }
@@ -137,6 +143,9 @@  static void fill_raw_fmts(struct hfi_plat_caps *cap, const void *fmts,
 {
 	const struct raw_formats *formats = fmts;
 
+	if (cap->num_fmts + num_fmts >= MAX_FMT_ENTRIES)
+		return;
+
 	memcpy(&cap->fmts[cap->num_fmts], formats, num_fmts * sizeof(*formats));
 	cap->num_fmts += num_fmts;
 }
@@ -159,6 +168,9 @@  parse_raw_formats(struct venus_core *core, u32 codecs, u32 domain, void *data)
 		rawfmts[i].buftype = fmt->buffer_type;
 		i++;
 
+		if (i >= MAX_FMT_ENTRIES)
+			return;
+
 		if (pinfo->num_planes > MAX_PLANES)
 			break;