From: Vikash Garodia <quic_vgarodia@quicinc.com>
Date: Thu, 20 Feb 2025 17:20:11 +0000 (+0530)
Subject: media: venus: hfi: add a check to handle OOB in sfr region
X-Git-Tag: v6.15-rc1~174^2~96
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=f4b211714bcc70effa60c34d9fa613d182e3ef1e;p=thirdparty%2Fkernel%2Flinux.git

media: venus: hfi: add a check to handle OOB in sfr region

sfr->buf_size is in shared memory and can be modified by malicious user.
OOB write is possible when the size is made higher than actual sfr data
buffer. Cap the size to allocated size for such cases.

Cc: stable@vger.kernel.org
Fixes: d96d3f30c0f2 ("[media] media: venus: hfi: add Venus HFI files")
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Vikash Garodia <quic_vgarodia@quicinc.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
---

diff --git a/drivers/media/platform/qcom/venus/hfi_venus.c b/drivers/media/platform/qcom/venus/hfi_venus.c
index 36d3a37db4e8a..b5f2ea8799507 100644
--- a/drivers/media/platform/qcom/venus/hfi_venus.c
+++ b/drivers/media/platform/qcom/venus/hfi_venus.c
@@ -1041,18 +1041,26 @@ static void venus_sfr_print(struct venus_hfi_device *hdev)
 {
 	struct device *dev = hdev->core->dev;
 	struct hfi_sfr *sfr = hdev->sfr.kva;
+	u32 size;
 	void *p;
 
 	if (!sfr)
 		return;
 
-	p = memchr(sfr->data, '\0', sfr->buf_size);
+	size = sfr->buf_size;
+	if (!size)
+		return;
+
+	if (size > ALIGNED_SFR_SIZE)
+		size = ALIGNED_SFR_SIZE;
+
+	p = memchr(sfr->data, '\0', size);
 	/*
 	 * SFR isn't guaranteed to be NULL terminated since SYS_ERROR indicates
 	 * that Venus is in the process of crashing.
 	 */
 	if (!p)
-		sfr->data[sfr->buf_size - 1] = '\0';
+		sfr->data[size - 1] = '\0';
 
 	dev_err_ratelimited(dev, "SFR message from FW: %s\n", sfr->data);
 }