From 4492d54d59872bb72e119ff9f77969ab4d8a0e6b Mon Sep 17 00:00:00 2001 From: Akash Goel Date: Tue, 21 Oct 2025 09:10:42 +0100 Subject: [PATCH] drm/panthor: Fix potential memleak of vma structure This commit addresses a memleak issue of panthor_vma (or drm_gpuva) structure in Panthor driver, that can happen if the GPU page table update operation to map the pages fail. The issue is very unlikely to occur in practice. v2: Add panthor_vm_op_ctx_return_vma() helper (Boris) v3: Add WARN_ON_ONCE (Boris) Fixes: 647810ec2476 ("drm/panthor: Add the MMU/VM logical block") Signed-off-by: Akash Goel Reviewed-by: Boris Brezillon Reviewed-by: Steven Price Signed-off-by: Steven Price Link: https://patch.msgid.link/20251021081042.1377406-1-akash.goel@arm.com --- drivers/gpu/drm/panthor/panthor_mmu.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/panthor/panthor_mmu.c b/drivers/gpu/drm/panthor/panthor_mmu.c index 58fead90533a6..6a41dfd7aaf33 100644 --- a/drivers/gpu/drm/panthor/panthor_mmu.c +++ b/drivers/gpu/drm/panthor/panthor_mmu.c @@ -1147,6 +1147,20 @@ static void panthor_vm_cleanup_op_ctx(struct panthor_vm_op_ctx *op_ctx, } } +static void +panthor_vm_op_ctx_return_vma(struct panthor_vm_op_ctx *op_ctx, + struct panthor_vma *vma) +{ + for (u32 i = 0; i < ARRAY_SIZE(op_ctx->preallocated_vmas); i++) { + if (!op_ctx->preallocated_vmas[i]) { + op_ctx->preallocated_vmas[i] = vma; + return; + } + } + + WARN_ON_ONCE(1); +} + static struct panthor_vma * panthor_vm_op_ctx_get_vma(struct panthor_vm_op_ctx *op_ctx) { @@ -2082,8 +2096,10 @@ static int panthor_gpuva_sm_step_map(struct drm_gpuva_op *op, void *priv) ret = panthor_vm_map_pages(vm, op->map.va.addr, flags_to_prot(vma->flags), op_ctx->map.sgt, op->map.gem.offset, op->map.va.range); - if (ret) + if (ret) { + panthor_vm_op_ctx_return_vma(op_ctx, vma); return ret; + } /* Ref owned by the mapping now, clear the obj field so we don't release the * pinning/obj ref behind GPUVA's back. -- 2.47.3