From eb3a41fd35e352fba387c4320a1fa0352f3e551c Mon Sep 17 00:00:00 2001 From: "Rob Herring (Arm)" Date: Thu, 27 Aug 2026 15:33:02 -0500 Subject: [PATCH] accel: ethosu: Ensure cmd stream ends with a stop op While the QSIZE register setting should prevent an out of bounds access of the command stream, it is not clear whether the h/w generates an interrupt in this case as is required (to prevent a timeout). As a stop op is expected end of the command stream, let's just ensure it is present. A stop op in the middle of the command stream also makes no sense. Fixes: 5a5e9c0228e6 ("accel: Add Arm Ethos-U NPU driver") Cc: stable@vger.kernel.org Reviewed-by: Frank Li Link: https://patch.msgid.link/20260827-ethosu-fixes-v1-3-346f9ea8791c@kernel.org Signed-off-by: Rob Herring (Arm) --- drivers/accel/ethosu/ethosu_device.h | 1 + drivers/accel/ethosu/ethosu_gem.c | 9 +++++++++ 2 files changed, 10 insertions(+) diff --git a/drivers/accel/ethosu/ethosu_device.h b/drivers/accel/ethosu/ethosu_device.h index d4458eac8447..1eca8590e68d 100644 --- a/drivers/accel/ethosu/ethosu_device.h +++ b/drivers/accel/ethosu/ethosu_device.h @@ -87,6 +87,7 @@ struct gen_pool; #define PMU_EV_TYPE_IDLE 0x20 enum ethosu_cmds { + NPU_OP_STOP = 0x0, NPU_OP_CONV = 0x2, NPU_OP_DEPTHWISE = 0x3, NPU_OP_POOL = 0x5, diff --git a/drivers/accel/ethosu/ethosu_gem.c b/drivers/accel/ethosu/ethosu_gem.c index fa37a190e9ff..9afe2549ec84 100644 --- a/drivers/accel/ethosu/ethosu_gem.c +++ b/drivers/accel/ethosu/ethosu_gem.c @@ -390,6 +390,7 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev, struct ethosu_validated_cmdstream_info __free(kfree) *info = kzalloc_obj(*info); struct ethosu_device *edev = to_ethosu_device(ddev); u32 *bocmds = bo->base.vaddr; + bool ends_with_stop = false; struct cmd_state st; int i, ret; @@ -426,6 +427,11 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev, } switch (cmd) { + case NPU_OP_STOP: + if (i != size / 4 - 1) + return -EINVAL; + ends_with_stop = true; + break; case NPU_OP_DMA_START: srclen = dma_length(info, &st.dma, &st.dma.src); dstlen = dma_length(info, &st.dma, &st.dma.dst); @@ -688,6 +694,9 @@ static int ethosu_gem_cmdstream_copy_and_validate(struct drm_device *ddev, } } + if (!ends_with_stop) + return -EINVAL; + for (i = 0; i < NPU_BASEP_REGION_MAX; i++) { if (!info->region_size[i]) continue;