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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Ofir Bitton <obitton@habana.ai>,
        Oded Gabbay <oded.gabbay@gmail.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 5.8 20/42] habanalabs: check correct vmalloc return code
Date:   Mon, 31 Aug 2020 11:29:12 -0400
Message-Id: <20200831152934.1023912-20-sashal@kernel.org>
In-Reply-To: <20200831152934.1023912-1-sashal@kernel.org>
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From: Ofir Bitton <obitton@habana.ai>

[ Upstream commit 0839152f8c1efc1cc2d515d1ff1e253ca9402ad3 ]

vmalloc can return different return code than NULL and a valid
pointer. We must validate it in order to dereference a non valid
pointer.

Signed-off-by: Ofir Bitton <obitton@habana.ai>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/misc/habanalabs/memory.c | 9 +++++++--
 drivers/misc/habanalabs/mmu.c    | 2 +-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/habanalabs/memory.c b/drivers/misc/habanalabs/memory.c
index 47da84a177197..e30b1b1877efa 100644
--- a/drivers/misc/habanalabs/memory.c
+++ b/drivers/misc/habanalabs/memory.c
@@ -66,6 +66,11 @@ static int alloc_device_memory(struct hl_ctx *ctx, struct hl_mem_in *args,
 	num_pgs = (args->alloc.mem_size + (page_size - 1)) >> page_shift;
 	total_size = num_pgs << page_shift;
 
+	if (!total_size) {
+		dev_err(hdev->dev, "Cannot allocate 0 bytes\n");
+		return -EINVAL;
+	}
+
 	contiguous = args->flags & HL_MEM_CONTIGUOUS;
 
 	if (contiguous) {
@@ -93,7 +98,7 @@ static int alloc_device_memory(struct hl_ctx *ctx, struct hl_mem_in *args,
 	phys_pg_pack->contiguous = contiguous;
 
 	phys_pg_pack->pages = kvmalloc_array(num_pgs, sizeof(u64), GFP_KERNEL);
-	if (!phys_pg_pack->pages) {
+	if (ZERO_OR_NULL_PTR(phys_pg_pack->pages)) {
 		rc = -ENOMEM;
 		goto pages_arr_err;
 	}
@@ -683,7 +688,7 @@ static int init_phys_pg_pack_from_userptr(struct hl_ctx *ctx,
 
 	phys_pg_pack->pages = kvmalloc_array(total_npages, sizeof(u64),
 						GFP_KERNEL);
-	if (!phys_pg_pack->pages) {
+	if (ZERO_OR_NULL_PTR(phys_pg_pack->pages)) {
 		rc = -ENOMEM;
 		goto page_pack_arr_mem_err;
 	}
diff --git a/drivers/misc/habanalabs/mmu.c b/drivers/misc/habanalabs/mmu.c
index a290d6b49d788..eb582bd4937ba 100644
--- a/drivers/misc/habanalabs/mmu.c
+++ b/drivers/misc/habanalabs/mmu.c
@@ -450,7 +450,7 @@ int hl_mmu_init(struct hl_device *hdev)
 	hdev->mmu_shadow_hop0 = kvmalloc_array(prop->max_asid,
 					prop->mmu_hop_table_size,
 					GFP_KERNEL | __GFP_ZERO);
-	if (!hdev->mmu_shadow_hop0) {
+	if (ZERO_OR_NULL_PTR(hdev->mmu_shadow_hop0)) {
 		rc = -ENOMEM;
 		goto err_pool_add;
 	}
-- 
2.25.1