On Mon, 22 Mar 2021, Arnd Bergmann wrote: > From: Arnd Bergmann <arnd@xxxxxxxx> > > gcc-11 introdces a harmless warning for cap_inode_getsecurity: > > security/commoncap.c: In function ‘cap_inode_getsecurity’: > security/commoncap.c:440:33: error: ‘memcpy’ reading 16 bytes from a region of size 0 [-Werror=stringop-overread] > 440 | memcpy(&nscap->data, &cap->data, sizeof(__le32) * 2 * VFS_CAP_U32); > | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > The problem here is that tmpbuf is initialized to NULL, so gcc assumes > it is not accessible unless it gets set by vfs_getxattr_alloc(). This is > a legitimate warning as far as I can tell, but the code is correct since > it correctly handles the error when that function fails. > > Add a separate NULL check to tell gcc about it as well. > > Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx> Applied to git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security.git fixes-v5.12 -- James Morris <jmorris@xxxxxxxxx>
