diff options
| author | Kees Cook <keescook@chromium.org> | 2022-12-01 16:23:25 -0800 |
|---|---|---|
| committer | Kees Cook <keescook@chromium.org> | 2022-12-02 13:04:44 -0800 |
| commit | bdc77507fecd00ddad2f502f86a48a9ec38f0f84 (patch) | |
| tree | 8c70f016ad598e4cbb9be00c31f405fbd3688b28 /arch/um | |
| parent | 3a017d6355f24de42f2ad688df9fa19e0cb128f2 (diff) | |
um: virt-pci: Avoid GCC non-NULL warning
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:100:9: 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: ba38961a069b ("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>
Diffstat (limited to 'arch/um')
| -rw-r--r-- | arch/um/drivers/virt-pci.c | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/arch/um/drivers/virt-pci.c b/arch/um/drivers/virt-pci.c index acb55b302b14..3ac220dafec4 100644 --- a/arch/um/drivers/virt-pci.c +++ b/arch/um/drivers/virt-pci.c @@ -97,7 +97,8 @@ static int um_pci_send_cmd(struct um_pci_device *dev, } buf = get_cpu_var(um_pci_msg_bufs); - memcpy(buf, cmd, cmd_size); + if (buf) + memcpy(buf, cmd, cmd_size); if (posted) { u8 *ncmd = kmalloc(cmd_size + extra_size, GFP_ATOMIC); @@ -182,6 +183,7 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset, struct um_pci_message_buffer *buf; u8 *data; unsigned long ret = ULONG_MAX; + size_t bytes = sizeof(buf->data); if (!dev) return ULONG_MAX; @@ -189,7 +191,8 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset, buf = get_cpu_var(um_pci_msg_bufs); data = buf->data; - memset(buf->data, 0xff, sizeof(buf->data)); + if (buf) + memset(data, 0xff, bytes); switch (size) { case 1: @@ -204,7 +207,7 @@ static unsigned long um_pci_cfgspace_read(void *priv, unsigned int offset, goto out; } - if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, 8)) + if (um_pci_send_cmd(dev, &hdr, sizeof(hdr), NULL, 0, data, bytes)) goto out; switch (size) { |