6.10-stable review patch. If anyone has any objections, please let me know.
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From: Maíra Canal mcanal@igalia.com
[ Upstream commit 497d370a644d95a9f04271aa92cb96d32e84c770 ]
When enabling UBSAN on Raspberry Pi 5, we get the following warning:
[ 387.894977] UBSAN: array-index-out-of-bounds in drivers/gpu/drm/v3d/v3d_sched.c:320:3 [ 387.903868] index 7 is out of range for type '__u32 [7]' [ 387.909692] CPU: 0 PID: 1207 Comm: kworker/u16:2 Tainted: G WC 6.10.3-v8-16k-numa #151 [ 387.919166] Hardware name: Raspberry Pi 5 Model B Rev 1.0 (DT) [ 387.925961] Workqueue: v3d_csd drm_sched_run_job_work [gpu_sched] [ 387.932525] Call trace: [ 387.935296] dump_backtrace+0x170/0x1b8 [ 387.939403] show_stack+0x20/0x38 [ 387.942907] dump_stack_lvl+0x90/0xd0 [ 387.946785] dump_stack+0x18/0x28 [ 387.950301] __ubsan_handle_out_of_bounds+0x98/0xd0 [ 387.955383] v3d_csd_job_run+0x3a8/0x438 [v3d] [ 387.960707] drm_sched_run_job_work+0x520/0x6d0 [gpu_sched] [ 387.966862] process_one_work+0x62c/0xb48 [ 387.971296] worker_thread+0x468/0x5b0 [ 387.975317] kthread+0x1c4/0x1e0 [ 387.978818] ret_from_fork+0x10/0x20 [ 387.983014] ---[ end trace ]---
This happens because the UAPI provides only seven configuration registers and we are reading the eighth position of this u32 array.
Therefore, fix the out-of-bounds read in `v3d_csd_job_run()` by accessing only seven positions on the '__u32 [7]' array. The eighth register exists indeed on V3D 7.1, but it isn't currently used. That being so, let's guarantee that it remains unused and add a note that it could be set in a future patch.
Fixes: 0ad5bc1ce463 ("drm/v3d: fix up register addresses for V3D 7.x") Reported-by: Tvrtko Ursulin tvrtko.ursulin@igalia.com Signed-off-by: Maíra Canal mcanal@igalia.com Reviewed-by: Iago Toral Quiroga itoral@igalia.com Link: https://patchwork.freedesktop.org/patch/msgid/20240809152001.668314-1-mcanal... Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/v3d/v3d_sched.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/v3d/v3d_sched.c b/drivers/gpu/drm/v3d/v3d_sched.c index 30d5366d62883..0132403b8159f 100644 --- a/drivers/gpu/drm/v3d/v3d_sched.c +++ b/drivers/gpu/drm/v3d/v3d_sched.c @@ -315,7 +315,7 @@ v3d_csd_job_run(struct drm_sched_job *sched_job) struct v3d_dev *v3d = job->base.v3d; struct drm_device *dev = &v3d->drm; struct dma_fence *fence; - int i, csd_cfg0_reg, csd_cfg_reg_count; + int i, csd_cfg0_reg;
v3d->csd_job = job;
@@ -335,9 +335,17 @@ v3d_csd_job_run(struct drm_sched_job *sched_job) v3d_switch_perfmon(v3d, &job->base);
csd_cfg0_reg = V3D_CSD_QUEUED_CFG0(v3d->ver); - csd_cfg_reg_count = v3d->ver < 71 ? 6 : 7; - for (i = 1; i <= csd_cfg_reg_count; i++) + for (i = 1; i <= 6; i++) V3D_CORE_WRITE(0, csd_cfg0_reg + 4 * i, job->args.cfg[i]); + + /* Although V3D 7.1 has an eighth configuration register, we are not + * using it. Therefore, make sure it remains unused. + * + * XXX: Set the CFG7 register + */ + if (v3d->ver >= 71) + V3D_CORE_WRITE(0, V3D_V7_CSD_QUEUED_CFG7, 0); + /* CFG0 write kicks off the job. */ V3D_CORE_WRITE(0, csd_cfg0_reg, job->args.cfg[0]);