linux-stable/include/uapi/linux/rpl.h
Kees Cook e8d283b6cf net: ipv6: rpl_iptunnel: Replace 0-length arrays with flexible arrays
Zero-length arrays are deprecated[1]. Replace struct ipv6_rpl_sr_hdr's
"segments" union of 0-length arrays with flexible arrays. Detected with
GCC 13, using -fstrict-flex-arrays=3:

In function 'rpl_validate_srh',
    inlined from 'rpl_build_state' at ../net/ipv6/rpl_iptunnel.c:96:7:
../net/ipv6/rpl_iptunnel.c:60:28: warning: array subscript <unknown> is outside array bounds of 'struct in6_addr[0]' [-Warray-bounds=]
   60 |         if (ipv6_addr_type(&srh->rpl_segaddr[srh->segments_left - 1]) &
      |                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from ../include/net/rpl.h:12,
                 from ../net/ipv6/rpl_iptunnel.c:13:
../include/uapi/linux/rpl.h: In function 'rpl_build_state':
../include/uapi/linux/rpl.h:40:33: note: while referencing 'addr'
   40 |                 struct in6_addr addr[0];
      |                                 ^~~~

[1] https://www.kernel.org/doc/html/latest/process/deprecated.html#zero-length-and-one-element-arrays

Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230105221533.never.711-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-01-06 19:28:01 -08:00

48 lines
864 B
C

/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */
/*
* IPv6 RPL-SR implementation
*
* Author:
* (C) 2020 Alexander Aring <alex.aring@gmail.com>
*/
#ifndef _UAPI_LINUX_RPL_H
#define _UAPI_LINUX_RPL_H
#include <asm/byteorder.h>
#include <linux/types.h>
#include <linux/in6.h>
/*
* RPL SR Header
*/
struct ipv6_rpl_sr_hdr {
__u8 nexthdr;
__u8 hdrlen;
__u8 type;
__u8 segments_left;
#if defined(__LITTLE_ENDIAN_BITFIELD)
__u32 cmpre:4,
cmpri:4,
reserved:4,
pad:4,
reserved1:16;
#elif defined(__BIG_ENDIAN_BITFIELD)
__u32 cmpri:4,
cmpre:4,
pad:4,
reserved:20;
#else
#error "Please fix <asm/byteorder.h>"
#endif
union {
__DECLARE_FLEX_ARRAY(struct in6_addr, addr);
__DECLARE_FLEX_ARRAY(__u8, data);
} segments;
} __attribute__((packed));
#define rpl_segaddr segments.addr
#define rpl_segdata segments.data
#endif