From: Norbert Slusarek <nslusarek@gmx.net> stable inclusion from stable-v5.10.102 commit 5d42865fc311af63785c9aa45ca30d1717c1c653 bugzilla: https://gitee.com/openeuler/kernel/issues/I567K6 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 2b17c400aeb44daf041627722581ade527bb3c1d upstream. A race condition was found in isotp_setsockopt() which allows to change socket options after the socket was bound. For the specific case of SF_BROADCAST support, this might lead to possible use-after-free because can_rx_unregister() is not called. Checking for the flag under the socket lock in isotp_bind() and taking the lock in isotp_setsockopt() fixes the issue. Fixes: 921ca574cd38 ("can: isotp: add SF_BROADCAST support for functional addressing") Link: https://lore.kernel.org/r/trinity-e6ae9efa-9afb-4326-84c0-f3609b9b8168-16207... Reported-by: Norbert Slusarek <nslusarek@gmx.net> Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com> Signed-off-by: Norbert Slusarek <nslusarek@gmx.net> Acked-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Oliver Hartkopp <socketcan@hartkopp.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yu Liao <liaoyu15@huawei.com> Reviewed-by: Wei Li <liwei391@huawei.com> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- net/can/isotp.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/net/can/isotp.c b/net/can/isotp.c index 37db4d232313..3f11d2b314b6 100644 --- a/net/can/isotp.c +++ b/net/can/isotp.c @@ -1193,16 +1193,13 @@ static int isotp_getname(struct socket *sock, struct sockaddr *uaddr, int peer) return ISOTP_MIN_NAMELEN; } -static int isotp_setsockopt(struct socket *sock, int level, int optname, +static int isotp_setsockopt_locked(struct socket *sock, int level, int optname, sockptr_t optval, unsigned int optlen) { struct sock *sk = sock->sk; struct isotp_sock *so = isotp_sk(sk); int ret = 0; - if (level != SOL_CAN_ISOTP) - return -EINVAL; - if (so->bound) return -EISCONN; @@ -1277,6 +1274,22 @@ static int isotp_setsockopt(struct socket *sock, int level, int optname, return ret; } +static int isotp_setsockopt(struct socket *sock, int level, int optname, + sockptr_t optval, unsigned int optlen) + +{ + struct sock *sk = sock->sk; + int ret; + + if (level != SOL_CAN_ISOTP) + return -EINVAL; + + lock_sock(sk); + ret = isotp_setsockopt_locked(sock, level, optname, optval, optlen); + release_sock(sk); + return ret; +} + static int isotp_getsockopt(struct socket *sock, int level, int optname, char __user *optval, int __user *optlen) { -- 2.20.1