From: Arnd Bergmann <arnd@arndb.de> stable inclusion from stable-v6.6.9 commit 7ee2ba3dd66b97f14c5b4a7867af87a94490993a category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8SU2D Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit a5812c68d849505ea657f653446512b85887f813 ] Turning on -Wstringop-overflow globally exposed a misleading compiler warning in bluetooth: net/bluetooth/hci_event.c: In function 'hci_cc_read_class_of_dev': net/bluetooth/hci_event.c:524:9: error: 'memcpy' writing 3 bytes into a region of size 0 overflows the destination [-Werror=stringop-overflow=] 524 | memcpy(hdev->dev_class, rp->dev_class, 3); | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The problem here is the check for hdev being NULL in bt_dev_dbg() that leads the compiler to conclude that hdev->dev_class might be an invalid pointer access. Add another explicit check for the same condition to make sure gcc sees this cannot happen. Fixes: a9de9248064b ("[Bluetooth] Switch from OGF+OCF to using only opcodes") Fixes: 1b56c90018f0 ("Makefile: Enable -Wstringop-overflow globally") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- net/bluetooth/hci_event.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index da756cbf6220..3661f8cdbab7 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -516,6 +516,9 @@ static u8 hci_cc_read_class_of_dev(struct hci_dev *hdev, void *data, { struct hci_rp_read_class_of_dev *rp = data; + if (WARN_ON(!hdev)) + return HCI_ERROR_UNSPECIFIED; + bt_dev_dbg(hdev, "status 0x%2.2x", rp->status); if (rp->status) -- 2.20.1