GCC (and Clang)[1] does not like having a partially allocated object,
since it cannot reason about it for bounds checking. Instead, fully
allocate struct carl9170_cmd.
Fix the following warnings Seen under GCC 13:
drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[4]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[4]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:161:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:162:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:163:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:164:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
drivers/net/wireless/ath/carl9170/cmd.c:220:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
Link: https://github.com/KSPP/linux/issues/268
Link: godbolt.org/z/KP97sxh3T [1]
Signed-off-by: Gustavo A. R. Silva <[email protected]>
---
drivers/net/wireless/ath/carl9170/cmd.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/wireless/ath/carl9170/cmd.c b/drivers/net/wireless/ath/carl9170/cmd.c
index f2b4f537e4c1..b8ed193c0195 100644
--- a/drivers/net/wireless/ath/carl9170/cmd.c
+++ b/drivers/net/wireless/ath/carl9170/cmd.c
@@ -120,7 +120,7 @@ struct carl9170_cmd *carl9170_cmd_buf(struct ar9170 *ar,
{
struct carl9170_cmd *tmp;
- tmp = kzalloc(sizeof(struct carl9170_cmd_head) + len, GFP_ATOMIC);
+ tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
if (tmp) {
tmp->hdr.cmd = cmd;
tmp->hdr.len = len;
--
2.34.1
On 3/17/23 18:30, Gustavo A. R. Silva wrote:
> GCC (and Clang)[1] does not like having a partially allocated object,
> since it cannot reason about it for bounds checking. Instead, fully
> allocate struct carl9170_cmd.
>
> Fix the following warnings Seen under GCC 13:
> drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[4]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[4]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:161:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:162:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:163:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:164:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:220:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
>
> Link: https://github.com/KSPP/linux/issues/268
> Link: godbolt.org/z/KP97sxh3T [1]
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
Acked-by: Christian Lamparter <[email protected]>
> ---
> drivers/net/wireless/ath/carl9170/cmd.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/net/wireless/ath/carl9170/cmd.c b/drivers/net/wireless/ath/carl9170/cmd.c
> index f2b4f537e4c1..b8ed193c0195 100644
> --- a/drivers/net/wireless/ath/carl9170/cmd.c
> +++ b/drivers/net/wireless/ath/carl9170/cmd.c
> @@ -120,7 +120,7 @@ struct carl9170_cmd *carl9170_cmd_buf(struct ar9170 *ar,
> {
> struct carl9170_cmd *tmp;
>
> - tmp = kzalloc(sizeof(struct carl9170_cmd_head) + len, GFP_ATOMIC);
> + tmp = kzalloc(sizeof(*tmp), GFP_ATOMIC);
This might throw-off people here. The reason this works is because carl9170_cmd struct
looks like this:
|
|struct carl9170_cmd {
| struct carl9170_cmd_head hdr; <-- 4 bytes
| union {
| struct carl9170_set_key_cmd setkey;
| [...]
| struct carl9170_rx_filter_cmd rx_filter;
| u8 data[CARL9170_MAX_CMD_PAYLOAD_LEN]; <---- that's 60 bytes
| } __packed __aligned(4);
|} __packed __aligned(4);
All commands have to fit into the command endpoint max size which is 64 bytes.
On Fri, Mar 17, 2023 at 11:30:47AM -0600, Gustavo A. R. Silva wrote:
> GCC (and Clang)[1] does not like having a partially allocated object,
> since it cannot reason about it for bounds checking. Instead, fully
> allocate struct carl9170_cmd.
>
> Fix the following warnings Seen under GCC 13:
> drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[4]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[4]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:161:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:162:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:163:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:164:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[20]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:125:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:126:30: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
> drivers/net/wireless/ath/carl9170/cmd.c:220:12: warning: array subscript ‘struct carl9170_cmd[0]’ is partly outside array bounds of ‘unsigned char[8]’ [-Warray-bounds=]
>
> Link: https://github.com/KSPP/linux/issues/268
> Link: godbolt.org/z/KP97sxh3T [1]
> Signed-off-by: Gustavo A. R. Silva <[email protected]>
Reviewed-by: Kees Cook <[email protected]>
--
Kees Cook