Messages in this thread | | | Date | Fri, 6 Jan 2023 10:03:27 -0600 | From | "Gustavo A. R. Silva" <> | Subject | Re: [PATCH] ipv6: ioam: Replace 0-length array with flexible array |
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On Thu, Jan 05, 2023 at 02:21:16PM -0800, Kees Cook wrote: > Zero-length arrays are deprecated[1]. Replace struct ioam6_trace_hdr's > "data" 0-length array with a flexible array. Detected with GCC 13, > using -fstrict-flex-arrays=3: > > net/ipv6/ioam6_iptunnel.c: In function 'ioam6_build_state': > net/ipv6/ioam6_iptunnel.c:194:37: warning: array subscript <unknown> is outside array bounds of '__u8[0]' {aka 'unsigned char[]'} [-Warray-bounds=] > 194 | tuninfo->traceh.data[trace->remlen * 4] = IPV6_TLV_PADN; > | ~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~ > In file included from include/linux/ioam6.h:11, > from net/ipv6/ioam6_iptunnel.c:13: > include/uapi/linux/ioam6.h:130:17: note: while referencing 'data' > 130 | __u8 data[0]; > | ^~~~ > > [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays > > Cc: "David S. Miller" <davem@davemloft.net> > Cc: Jakub Kicinski <kuba@kernel.org> > Cc: Justin Iurman <justin.iurman@uliege.be> > Cc: Eric Dumazet <edumazet@google.com> > Cc: Paolo Abeni <pabeni@redhat.com> > Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org> > Cc: netdev@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Thanks! -- Gustavo
> --- > include/uapi/linux/ioam6.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/uapi/linux/ioam6.h b/include/uapi/linux/ioam6.h > index ac4de376f0ce..8f72b24fefb3 100644 > --- a/include/uapi/linux/ioam6.h > +++ b/include/uapi/linux/ioam6.h > @@ -127,7 +127,7 @@ struct ioam6_trace_hdr { > #endif > > #define IOAM6_TRACE_DATA_SIZE_MAX 244 > - __u8 data[0]; > + __u8 data[]; > } __attribute__((packed)); > > #endif /* _UAPI_LINUX_IOAM6_H */ > -- > 2.34.1 >
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