commit bdc77507fe upstream.
GCC gets confused about the return value of get_cpu_var() possibly
being NULL, so explicitly test for it before calls to memcpy() and
memset(). Avoids warnings like this:
arch/um/drivers/virt-pci.c: In function 'um_pci_send_cmd':
include/linux/fortify-string.h:48:33: warning: argument 1 null where non-null expected [-Wnonnull]
48 | #define __underlying_memcpy __builtin_memcpy
| ^
include/linux/fortify-string.h:438:9: note: in expansion of macro '__underlying_memcpy'
438 | __underlying_##op(p, q, __fortify_size); \
| ^~~~~~~~~~~~~
include/linux/fortify-string.h:483:26: note: in expansion of macro '__fortify_memcpy_chk'
483 | #define memcpy(p, q, s) __fortify_memcpy_chk(p, q, s, \
| ^~~~~~~~~~~~~~~~~~~~
arch/um/drivers/virt-pci.c💯9: note: in expansion of macro 'memcpy'
100 | memcpy(buf, cmd, cmd_size);
| ^~~~~~
While at it, avoid literal "8" and use stored sizeof(buf->data) in
memset() and um_pci_send_cmd().
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/202211271212.SUZSC9f9-lkp@intel.com
Fixes: ba38961a06 ("um: Enable FORTIFY_SOURCE")
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Xiu Jianfeng <xiujianfeng@huawei.com>
Cc: Vincent Whitchurch <vincent.whitchurch@axis.com>
Cc: linux-um@lists.infradead.org
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
d93b6a8a34