[PATCH 4/5] gpu: drm: amdgpu: Replace snprintf() with sysfs_emit()

From: Sumera Priyadarsini <sylphrenadin@gmail.com>
To: dri-devel@lists.freedesktop.org
Cc: outreachy-kernel@googlegroups.com, alexander.deucher@amd.com,
	christian.koenig@amd.com, airlied@linux.ie, daniel@ffwll.ch,
	melissa.srw@gmail.com, linux-media@vger.kernel.org,
	amd-gfx@lists.freedesktop.org, linux-kernel@vger.kernel.org
Subject: [PATCH 4/5] gpu: drm: amdgpu: Replace snprintf() with sysfs_emit()
Date: Thu, 22 Oct 2020 19:17:56 +0530	[thread overview]
Message-ID: <f6107f3e467f1906abdcc33d35f13cf54f7e5a96.1603371258.git.sylphrenadin@gmail.com> (raw)
In-Reply-To: <cover.1603371258.git.sylphrenadin@gmail.com>

Using snprintf() for show() methods holds the risk of buffer overrun
as snprintf() does not know the PAGE_SIZE maximum of the temporary
buffer used to output sysfs content.

Modify amdgpu_psp.c to use sysfs_emit() instead which knows the
size of the temporary buffer.

Issue found with Coccinelle.

Signed-off-by: Sumera Priyadarsini <sylphrenadin@gmail.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
index d6c38e24f130..4d1d1e1b005d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_psp.c
@@ -2621,7 +2621,7 @@ static ssize_t psp_usbc_pd_fw_sysfs_read(struct device *dev,
 		return ret;
 	}
 
-	return snprintf(buf, PAGE_SIZE, "%x\n", fw_ver);
+	return sysfs_emit(buf, PAGE_SIZE, "%x\n", fw_ver);
 }
 
 static ssize_t psp_usbc_pd_fw_sysfs_write(struct device *dev,
-- 
2.25.1

