This is a note to let you know that I've just added the patch titled ipv4: prevent potential spectre v1 gadget in fib_metrics_match() to the 6.1-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-fib_metr.patch and it can be found in the queue-6.1 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e20f0629ade7755d891fcec6e49cf0179c0045c1 Author: Eric Dumazet <edumazet@xxxxxxxxxx> Date: Fri Jan 20 13:31:40 2023 +0000 ipv4: prevent potential spectre v1 gadget in fib_metrics_match() [ Upstream commit 5e9398a26a92fc402d82ce1f97cc67d832527da0 ] if (!type) continue; if (type > RTAX_MAX) return false; ... fi_val = fi->fib_metrics->metrics[type - 1]; @type being used as an array index, we need to prevent cpu speculation or risk leaking kernel memory content. Fixes: 5f9ae3d9e7e4 ("ipv4: do metrics match when looking up and deleting a route") Signed-off-by: Eric Dumazet <edumazet@xxxxxxxxxx> Link: https://lore.kernel.org/r/20230120133140.3624204-1-edumazet@xxxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c index ce9ff3c62e84..3bb890a40ed7 100644 --- a/net/ipv4/fib_semantics.c +++ b/net/ipv4/fib_semantics.c @@ -30,6 +30,7 @@ #include <linux/slab.h> #include <linux/netlink.h> #include <linux/hash.h> +#include <linux/nospec.h> #include <net/arp.h> #include <net/inet_dscp.h> @@ -1022,6 +1023,7 @@ bool fib_metrics_match(struct fib_config *cfg, struct fib_info *fi) if (type > RTAX_MAX) return false; + type = array_index_nospec(type, RTAX_MAX + 1); if (type == RTAX_CC_ALGO) { char tmp[TCP_CA_NAME_MAX]; bool ecn_ca = false;