This is a note to let you know that I've just added the patch titled
net/sched: flower: fix possible OOB write in fl_set_geneve_opt()
to the 4.19-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:
net-sched-flower-fix-possible-oob-write-in-fl_set_ge.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit afad755dde309bffa2719a173a48a5a7505aaa25
Author: Hangyu Hua <hbh25y@xxxxxxxxx>
Date: Wed May 31 18:28:04 2023 +0800
net/sched: flower: fix possible OOB write in fl_set_geneve_opt()
[ Upstream commit 4d56304e5827c8cc8cc18c75343d283af7c4825c ]
If we send two TCA_FLOWER_KEY_ENC_OPTS_GENEVE packets and their total
size is 252 bytes(key->enc_opts.len = 252) then
key->enc_opts.len = opt->length = data_len / 4 = 0 when the third
TCA_FLOWER_KEY_ENC_OPTS_GENEVE packet enters fl_set_geneve_opt. This
bypasses the next bounds check and results in an out-of-bounds.
Fixes: 0a6e77784f49 ("net/sched: allow flower to match tunnel options")
Signed-off-by: Hangyu Hua <hbh25y@xxxxxxxxx>
Reviewed-by: Simon Horman <simon.horman@xxxxxxxxxxxx>
Reviewed-by: Pieter Jansen van Vuuren <pieter.jansen-van-vuuren@xxxxxxx>
Link: https://lore.kernel.org/r/20230531102805.27090-1-hbh25y@xxxxxxxxx
Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 6163648145c19..7ffa28a98d743 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -640,6 +640,9 @@ static int fl_set_geneve_opt(const struct nlattr *nla, struct fl_flow_key *key,
if (option_len > sizeof(struct geneve_opt))
data_len = option_len - sizeof(struct geneve_opt);
+ if (key->enc_opts.len > FLOW_DIS_TUN_OPTS_MAX - 4)
+ return -ERANGE;
+
opt = (struct geneve_opt *)&key->enc_opts.data[key->enc_opts.len];
memset(opt, 0xff, option_len);
opt->length = data_len / 4;
