[PATCH 5.4 065/154] drm/radeon: fix uninitialized size issue in radeon_vce_cs_parse()

Greg Kroah-Hartman
2025-04-08T12:05:11Z

From: Nikita Zhandarovich <n.zhandarovich@fintech.ru>

commit dd8689b52a24807c2d5ce0a17cb26dc87f75235c upstream.

On the off chance that command stream passed from userspace via
ioctl() call to radeon_vce_cs_parse() is weirdly crafted and
first command to execute is to encode (case 0x03000001), the function
in question will attempt to call radeon_vce_cs_reloc() with size
argument that has not been properly initialized. Specifically, 'size'
will point to 'tmp' variable before the latter had a chance to be
assigned any value.

Play it safe and init 'tmp' with 0, thus ensuring that
radeon_vce_cs_reloc() will catch an early error in cases like these.

Found by Linux Verification Center (linuxtesting.org) with static
analysis tool SVACE.

Fixes: 2fc5703abda2 ("drm/radeon: check VCE relocation buffer range v3")
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 2d52de55f9ee7aaee0e09ac443f77855989c6b68)
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/radeon/radeon_vce.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/radeon/radeon_vce.c
+++ b/drivers/gpu/drm/radeon/radeon_vce.c
@@ -558,7 +558,7 @@ int radeon_vce_cs_parse(struct radeon_cs
{
int session_idx = -1;
bool destroyed = false, created = false, allocated = false;
- uint32_t tmp, handle = 0;
+ uint32_t tmp = 0, handle = 0;
uint32_t *size = &tmp;
int i, r = 0;