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@ 2024-03-28 10:28 Maxim Korotkov
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From: Maxim Korotkov @ 2024-03-28 10:28 UTC (permalink / raw)
  To: Kenneth Chan
  Cc: Maxim Korotkov, Len Brown, Henrique de Moraes Holschuh,
	Harald Welte, Matthew Garrett, Ivan Kapranov, lvc-project,
	platform-driver-x86, linux-kernel

Date: Thu, 28 Mar 2024 11:22:37 +0300
Subject: [PATCH] platform/x86: panasonic-laptop: fix NULL dereference

When initializing the pcc by calling acpi_driver_data(), the "device"
pointer was dereferenced without checking for NULL. This seems like
a logical mistake.

Added a pointer check to ensure that it is valid
before using it for pcc initialization.

Found by Security Code and Linux Verification Center(linuxtesting.org)

Fixes: 709ee531c153 ("panasonic-laptop: add Panasonic Let's Note laptop extras driver v0.94")

Signed-off-by: Maxim Korotkov <korotkov.maxim.s@gmail.com>
---
 drivers/platform/x86/panasonic-laptop.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/panasonic-laptop.c b/drivers/platform/x86/panasonic-laptop.c
index cf845ee1c7b1..de29758b0384 100644
--- a/drivers/platform/x86/panasonic-laptop.c
+++ b/drivers/platform/x86/panasonic-laptop.c
@@ -1067,9 +1067,12 @@ static int acpi_pcc_hotkey_add(struct acpi_device *device)
 
 static void acpi_pcc_hotkey_remove(struct acpi_device *device)
 {
-	struct pcc_acpi *pcc = acpi_driver_data(device);
+	struct pcc_acpi *pcc;
 
-	if (!device || !pcc)
+	if (!device)
+		return;
+	pcc = acpi_driver_data(device);
+	if (!pcc)
 		return;
 
 	i8042_remove_filter(panasonic_i8042_filter);
-- 
2.34.1


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