This is a note to let you know that I've just added the patch titled ipv6: fix ndisc_is_useropt() handling for PIO to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: ipv6-fix-ndisc_is_useropt-handling-for-pio.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit c8b7be8fef6b1e002a6e82b9173dca84c2e7592c Author: Maciej Żenczykowski <maze@xxxxxxxxxx> Date: Mon Jul 29 17:17:48 2024 -0700 ipv6: fix ndisc_is_useropt() handling for PIO [ 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> diff --git a/net/ipv6/ndisc.c b/net/ipv6/ndisc.c index 68debc78189c2..2062ab94721e3 100644 --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -227,6 +227,7 @@ struct ndisc_options *ndisc_parse_options(const struct net_device *dev, 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; @@ -262,22 +263,23 @@ struct ndisc_options *ndisc_parse_options(const struct net_device *dev, 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;