--- /dev/null
+From fc68f42aa737dc15e7665a4101d4168aadb8e4c4 Mon Sep 17 00:00:00 2001
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Date: Sat, 24 Jul 2021 15:25:54 -0700
+Subject: ACPI: fix NULL pointer dereference
+
+From: Linus Torvalds <torvalds@linux-foundation.org>
+
+commit fc68f42aa737dc15e7665a4101d4168aadb8e4c4 upstream.
+
+Commit 71f642833284 ("ACPI: utils: Fix reference counting in
+for_each_acpi_dev_match()") started doing "acpi_dev_put()" on a pointer
+that was possibly NULL. That fails miserably, because that helper
+inline function is not set up to handle that case.
+
+Just make acpi_dev_put() silently accept a NULL pointer, rather than
+calling down to put_device() with an invalid offset off that NULL
+pointer.
+
+Link: https://lore.kernel.org/lkml/a607c149-6bf6-0fd0-0e31-100378504da2@kernel.dk/
+Reported-and-tested-by: Jens Axboe <axboe@kernel.dk>
+Tested-by: Daniel Scally <djrscally@gmail.com>
+Cc: Andy Shevchenko <andy.shevchenko@gmail.com>
+Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+---
+ include/acpi/acpi_bus.h | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+--- a/include/acpi/acpi_bus.h
++++ b/include/acpi/acpi_bus.h
+@@ -711,7 +711,8 @@ static inline struct acpi_device *acpi_d
+
+ static inline void acpi_dev_put(struct acpi_device *adev)
+ {
+- put_device(&adev->dev);
++ if (adev)
++ put_device(&adev->dev);
+ }
+ #else /* CONFIG_ACPI */
+