diff options
| author | Wang Yufen <wangyufen@huawei.com> | 2022-06-07 20:00:28 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-06-22 14:27:54 +0200 |
| commit | 034246122f5c5e2e2a0b9fe04e24517920e9beb1 (patch) | |
| tree | 90d38bb4c094f9f8a82f4411aca172845f913e9e | |
| parent | 84dc940890e91e42898e4443a093281702440abf (diff) | |
| download | linux-stable-034246122f5c5e2e2a0b9fe04e24517920e9beb1.tar.gz | |
ipv6: Fix signed integer overflow in l2tp_ip6_sendmsg
[ Upstream commit f638a84afef3dfe10554c51820c16e39a278c915 ]
When len >= INT_MAX - transhdrlen, ulen = len + transhdrlen will be
overflow. To fix, we can follow what udpv6 does and subtract the
transhdrlen from the max.
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Link: https://lore.kernel.org/r/20220607120028.845916-2-wangyufen@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | net/l2tp/l2tp_ip6.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/net/l2tp/l2tp_ip6.c b/net/l2tp/l2tp_ip6.c index 96f975777438..d54dbd01d86f 100644 --- a/net/l2tp/l2tp_ip6.c +++ b/net/l2tp/l2tp_ip6.c @@ -502,14 +502,15 @@ static int l2tp_ip6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) struct ipcm6_cookie ipc6; int addr_len = msg->msg_namelen; int transhdrlen = 4; /* zero session-id */ - int ulen = len + transhdrlen; + int ulen; int err; /* Rough check on arithmetic overflow, * better check is made in ip6_append_data(). */ - if (len > INT_MAX) + if (len > INT_MAX - transhdrlen) return -EMSGSIZE; + ulen = len + transhdrlen; /* Mirror BSD error message compatibility */ if (msg->msg_flags & MSG_OOB) |