From 39e505c38ffcc845ea58259573ff34c6d98e36bb Mon Sep 17 00:00:00 2001 From: Bill Wendling Date: Fri, 25 Sep 2026 21:25:52 +0000 Subject: [PATCH] firewire: core: add __counted_by_ptr attribute to struct fw_device The GCC and Clang attribute '__counted_by_ptr' associates a pointer field with an integer field holding its element count. This enables runtime bounds checking by KASAN and UBSAN to prevent out-of-bounds accesses to the pointer. In 'struct fw_device' (defined in 'include/linux/firewire.h'), the field 'config_rom' is a pointer to the device's Configuration ROM data, and its associated element count is stored in 'config_rom_length'. Additionally, update the existing KUnit test in 'drivers/firewire/device-attribute-test.c' where 'config_rom_length' was incorrectly initialized with the byte size ('sizeof(simple_avc_config_rom)') instead of the element count ('ARRAY_SIZE(simple_avc_config_rom)'). This ensures the '__counted_by_ptr' bounds-checking annotation does not trigger any false-positive panics or compile/runtime checks. Cc: codemender-patching+linux@google.com Assisted-by: LLM Signed-off-by: Bill Wendling Link: https://lore.kernel.org/r/20260925212552.125652-1-morbo@google.com Signed-off-by: Takashi Sakamoto --- drivers/firewire/device-attribute-test.c | 4 ++-- include/linux/firewire.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/firewire/device-attribute-test.c b/drivers/firewire/device-attribute-test.c index 97478a96d1c9..2c482afca8f1 100644 --- a/drivers/firewire/device-attribute-test.c +++ b/drivers/firewire/device-attribute-test.c @@ -86,7 +86,7 @@ static void device_attr_simple_avc(struct kunit *test) .type = &fw_device_type, }, .config_rom = simple_avc_config_rom, - .config_rom_length = sizeof(simple_avc_config_rom), + .config_rom_length = ARRAY_SIZE(simple_avc_config_rom), }; static const struct fw_unit unit0 = { .device = { @@ -168,7 +168,7 @@ static void device_attr_legacy_avc(struct kunit *test) .type = &fw_device_type, }, .config_rom = legacy_avc_config_rom, - .config_rom_length = sizeof(legacy_avc_config_rom), + .config_rom_length = ARRAY_SIZE(legacy_avc_config_rom), }; static const struct fw_unit unit0 = { .device = { diff --git a/include/linux/firewire.h b/include/linux/firewire.h index 9d5a42724f1a..dbb5c825a1cc 100644 --- a/include/linux/firewire.h +++ b/include/linux/firewire.h @@ -224,7 +224,7 @@ struct fw_device { struct mutex client_list_mutex; struct list_head client_list; - const u32 *config_rom; + const u32 *config_rom __counted_by_ptr(config_rom_length); size_t config_rom_length; int config_rom_retries; unsigned is_local:1;