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Thu, 07 May 2026 18:57:31 -0700 (PDT) Received: from tux ([2601:7c0:c37e:2360::111d]) by smtp.gmail.com with ESMTPSA id 956f58d0204a3-65d96c36171sm102786d50.20.2026.05.07.18.57.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 07 May 2026 18:57:31 -0700 (PDT) From: Ethan Tidmore To: Krzysztof Kozlowski , Thierry Reding , Jonathan Hunter Cc: Mikko Perttunen , Kees Cook , Svyatoslav Ryhel , linux-tegra@vger.kernel.org, linux-kernel@vger.kernel.org, Ethan Tidmore Subject: [PATCH] memory: tegra: Fix possible null pointer dereference Date: Thu, 7 May 2026 20:57:16 -0500 Message-ID: <20260508015716.652347-1-ethantidmore06@gmail.com> X-Mailer: git-send-email 2.54.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The function tegra114_emc_find_timing() has the possibility of returning null and it's return value 'timing' is dereferenced before it is checked for null. Place dereference after null pointer check. Detected by Smatch: drivers/memory/tegra/tegra114-emc.c:520 tegra114_emc_prepare_timing_change() warn: variable dereferenced before check 'timing' (see line 515) Fixes: dce208b5405f4 ("memory: tegra: Add Tegra114 EMC driver") Signed-off-by: Ethan Tidmore --- drivers/memory/tegra/tegra114-emc.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/memory/tegra/tegra114-emc.c b/drivers/memory/tegra/tegra114-emc.c index be6c699cb656..fc3bf1a28630 100644 --- a/drivers/memory/tegra/tegra114-emc.c +++ b/drivers/memory/tegra/tegra114-emc.c @@ -512,14 +512,16 @@ static int tegra114_emc_prepare_timing_change(struct tegra_emc *emc, enum emc_dll_change dll_change; unsigned int pre_wait = 0; u32 val, mask; - bool next_dll_enabled = !(timing->emc_mode_1 & 0x1); bool last_dll_enabled = !(last->emc_mode_1 & 0x1); bool update = false; + bool next_dll_enabled; unsigned int i; if (!timing) return -ENOENT; + next_dll_enabled = !(timing->emc_mode_1 & 0x1); + if (next_dll_enabled == last_dll_enabled) dll_change = DLL_CHANGE_NONE; else if (next_dll_enabled) -- 2.54.0