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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, QintaoShen <unSimple1993@163.com>,
        Alex Deucher <alexander.deucher@amd.com>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.4 20/63] drm/amdkfd: Check for potential null return of kmalloc_array()
Date:   Mon, 18 Apr 2022 14:13:17 +0200
Message-Id: <20220418121135.509037944@linuxfoundation.org>
In-Reply-To: <20220418121134.149115109@linuxfoundation.org>
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From: QintaoShen <unSimple1993@163.com>

[ Upstream commit ebbb7bb9e80305820dc2328a371c1b35679f2667 ]

As the kmalloc_array() may return null, the 'event_waiters[i].wait' would lead to null-pointer dereference.
Therefore, it is better to check the return value of kmalloc_array() to avoid this confusion.

Signed-off-by: QintaoShen <unSimple1993@163.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/amd/amdkfd/kfd_events.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_events.c b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
index d674d4b3340f..adbb2fec2e0f 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_events.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_events.c
@@ -532,6 +532,8 @@ static struct kfd_event_waiter *alloc_event_waiters(uint32_t num_events)
 	event_waiters = kmalloc_array(num_events,
 					sizeof(struct kfd_event_waiter),
 					GFP_KERNEL);
+	if (!event_waiters)
+		return NULL;
 
 	for (i = 0; (event_waiters) && (i < num_events) ; i++) {
 		init_wait(&event_waiters[i].wait);
-- 
2.35.1