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 5.10-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-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 2ab1727ad1a2941ee595b6e767cba968be0bf8b3
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 ab9fcc6231b8..4e94796ccdbd 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/ip.h>
@@ -1021,6 +1022,7 @@ 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;
