From bbc2fde6d98c21304546ecb48a4956c81327db5b Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 24 Jul 2021 15:25:54 -0700 Subject: [PATCH] ACPI: fix NULL pointer dereference [ Upstream commit fc68f42aa737dc15e7665a4101d4168aadb8e4c4 ] 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 Tested-by: Daniel Scally Cc: Andy Shevchenko Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- include/acpi/acpi_bus.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 37dac195adbb..6ad3b89a8a2e 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -689,7 +689,8 @@ acpi_dev_get_first_match_dev(const char *hid, const char *uid, s64 hrv); static inline void acpi_dev_put(struct acpi_device *adev) { - put_device(&adev->dev); + if (adev) + put_device(&adev->dev); } #else /* CONFIG_ACPI */