[PATCH 5.10 094/130] drm/msm/a6xx: Allocate enough space for GMU registers

Greg Kroah-Hartman
2021-12-06T15:31:31Z

From: Douglas Anderson <dianders@chromium.org>

commit b4d25abf9720b69a03465b09d0d62d1998ed6708 upstream.

In commit 142639a52a01 ("drm/msm/a6xx: fix crashstate capture for
A650") we changed a6xx_get_gmu_registers() to read 3 sets of
registers. Unfortunately, we didn't change the memory allocation for
the array. That leads to a KASAN warning (this was on the chromeos-5.4
kernel, which has the problematic commit backported to it):

BUG: KASAN: slab-out-of-bounds in _a6xx_get_gmu_registers+0x144/0x430
Write of size 8 at addr ffffff80c89432b0 by task A618-worker/209
CPU: 5 PID: 209 Comm: A618-worker Tainted: G W 5.4.156-lockdep #22
Hardware name: Google Lazor Limozeen without Touchscreen (rev5 - rev8) (DT)
Call trace:
dump_backtrace+0x0/0x248
show_stack+0x20/0x2c
dump_stack+0x128/0x1ec
print_address_description+0x88/0x4a0
__kasan_report+0xfc/0x120
kasan_report+0x10/0x18
__asan_report_store8_noabort+0x1c/0x24
_a6xx_get_gmu_registers+0x144/0x430
a6xx_gpu_state_get+0x330/0x25d4
msm_gpu_crashstate_capture+0xa0/0x84c
recover_worker+0x328/0x838
kthread_worker_fn+0x32c/0x574
kthread+0x2dc/0x39c
ret_from_fork+0x10/0x18

Allocated by task 209:
__kasan_kmalloc+0xfc/0x1c4
kasan_kmalloc+0xc/0x14
kmem_cache_alloc_trace+0x1f0/0x2a0
a6xx_gpu_state_get+0x164/0x25d4
msm_gpu_crashstate_capture+0xa0/0x84c
recover_worker+0x328/0x838
kthread_worker_fn+0x32c/0x574
kthread+0x2dc/0x39c
ret_from_fork+0x10/0x18

Fixes: 142639a52a01 ("drm/msm/a6xx: fix crashstate capture for A650")
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20211103153049.1.Idfa574ccb529d17b69db3a1852e49b580132035c@changeid
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu_state.c
@@ -777,12 +777,12 @@ static void a6xx_get_gmu_registers(struc
struct a6xx_gpu *a6xx_gpu = to_a6xx_gpu(adreno_gpu);

a6xx_state->gmu_registers = state_kcalloc(a6xx_state,
- 2, sizeof(*a6xx_state->gmu_registers));
+ 3, sizeof(*a6xx_state->gmu_registers));

if (!a6xx_state->gmu_registers)
return;

- a6xx_state->nr_gmu_registers = 2;
+ a6xx_state->nr_gmu_registers = 3;

/* Get the CX GMU registers from AHB */
_a6xx_get_gmu_registers(gpu, a6xx_state, &a6xx_gmu_reglist[0],