Re: [PATCH][next] carl9170: Fix multiple -Warray-bounds warnings

From: Kees Cook
Date: Mon Mar 20 2023 - 13:41:45 EST


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 <gustavoars@xxxxxxxxxx>

Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>

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Kees Cook