4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Maciej Żenczykowski <maze@xxxxxxxxxx> [ Upstream commit a46c68debf3be3a477a69ccbf0a1d050df841676 ] The current logic only works if the PIO is between two other ND user options. This fixes it so that the PIO can also be either before or after other ND user options (for example the first or last option in the RA). side note: there's actually Android tests verifying a portion of the old broken behaviour, so: https://android-review.googlesource.com/c/kernel/tests/+/3196704 fixes those up. Cc: Jen Linkova <furry@xxxxxxxxxx> Cc: Lorenzo Colitti <lorenzo@xxxxxxxxxx> Cc: Patrick Rohr <prohr@xxxxxxxxxx> Cc: David Ahern <dsahern@xxxxxxxxxx> Cc: YOSHIFUJI Hideaki / 吉藤英明 <yoshfuji@xxxxxxxxxxxxxx> Cc: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Maciej Żenczykowski <maze@xxxxxxxxxx> Fixes: 048c796beb6e ("ipv6: adjust ndisc_is_useropt() to also return true for PIO") Link: https://patch.msgid.link/20240730001748.147636-1-maze@xxxxxxxxxx Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- net/ipv6/ndisc.c | 34 ++++++++++++++++++---------------- 1 file changed, 18 insertions(+), 16 deletions(-) --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -223,6 +223,7 @@ struct ndisc_options *ndisc_parse_option return NULL; memset(ndopts, 0, sizeof(*ndopts)); while (opt_len) { + bool unknown = false; int l; if (opt_len < sizeof(struct nd_opt_hdr)) return NULL; @@ -258,22 +259,23 @@ struct ndisc_options *ndisc_parse_option break; #endif default: - if (ndisc_is_useropt(dev, nd_opt)) { - ndopts->nd_useropts_end = nd_opt; - if (!ndopts->nd_useropts) - ndopts->nd_useropts = nd_opt; - } else { - /* - * Unknown options must be silently ignored, - * to accommodate future extension to the - * protocol. - */ - ND_PRINTK(2, notice, - "%s: ignored unsupported option; type=%d, len=%d\n", - __func__, - nd_opt->nd_opt_type, - nd_opt->nd_opt_len); - } + unknown = true; + } + if (ndisc_is_useropt(dev, nd_opt)) { + ndopts->nd_useropts_end = nd_opt; + if (!ndopts->nd_useropts) + ndopts->nd_useropts = nd_opt; + } else if (unknown) { + /* + * Unknown options must be silently ignored, + * to accommodate future extension to the + * protocol. + */ + ND_PRINTK(2, notice, + "%s: ignored unsupported option; type=%d, len=%d\n", + __func__, + nd_opt->nd_opt_type, + nd_opt->nd_opt_len); } next_opt: opt_len -= l;
