This is a note to let you know that I've just added the patch titled ipv4: prevent potential spectre v1 gadget in ip_metrics_convert() to the 5.15-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: ipv4-prevent-potential-spectre-v1-gadget-in-ip_metri.patch and it can be found in the queue-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 2defde978133a1a8c31bb431bfaa5439fb69f662 Author: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Fri Jan 20 13:30:40 2023 +0000 ipv4: prevent potential spectre v1 gadget in ip_metrics_convert() [ Upstream commit 1d1d63b612801b3f0a39b7d4467cad0abd60e5c8 ] if (!type) continue; if (type > RTAX_MAX) return -EINVAL; ... metrics[type - 1] = val; @type being used as an array index, we need to prevent cpu speculation or risk leaking kernel memory content. Fixes: 6cf9dfd3bd62 ("net: fib: move metrics parsing to a helper") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230120133040.3623463-1-edumazet@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv4/metrics.c b/net/ipv4/metrics.c index 25ea6ac44db9..6a1427916c7d 100644 --- a/net/ipv4/metrics.c +++ b/net/ipv4/metrics.c @@ -1,5 +1,6 @@ // SPDX-License-Identifier: GPL-2.0-only #include <linux/netlink.h> +#include <linux/nospec.h> #include <linux/rtnetlink.h> #include <linux/types.h> #include <net/ip.h> @@ -28,6 +29,7 @@ static int ip_metrics_convert(struct net *net, struct nlattr *fc_mx, return -EINVAL; } + type = array_index_nospec(type, RTAX_MAX + 1); if (type == RTAX_CC_ALGO) { char tmp[TCP_CA_NAME_MAX];