5.15-stable review patch. If anyone has any objections, please let me know.
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From: Jakub Kicinski kuba@kernel.org
[ Upstream commit 5071a1e606b30c0c11278d3c6620cd6a24724cf6 ]
syzbot discovered that it can disconnect a TLS socket and then run into all sort of unexpected corner cases. I have a vague recollection of Eric pointing this out to us a long time ago. Supporting disconnect is really hard, for one thing if offload is enabled we'd need to wait for all packets to be _acked_. Disconnect is not commonly used, disallow it.
The immediate problem syzbot run into is the warning in the strp, but that's just the easiest bug to trigger:
WARNING: CPU: 0 PID: 5834 at net/tls/tls_strp.c:486 tls_strp_msg_load+0x72e/0xa80 net/tls/tls_strp.c:486 RIP: 0010:tls_strp_msg_load+0x72e/0xa80 net/tls/tls_strp.c:486 Call Trace: <TASK> tls_rx_rec_wait+0x280/0xa60 net/tls/tls_sw.c:1363 tls_sw_recvmsg+0x85c/0x1c30 net/tls/tls_sw.c:2043 inet6_recvmsg+0x2c9/0x730 net/ipv6/af_inet6.c:678 sock_recvmsg_nosec net/socket.c:1023 [inline] sock_recvmsg+0x109/0x280 net/socket.c:1045 __sys_recvfrom+0x202/0x380 net/socket.c:2237
Fixes: 3c4d7559159b ("tls: kernel TLS support") Reported-by: syzbot+b4cd76826045a1eb93c1@syzkaller.appspotmail.com Signed-off-by: Jakub Kicinski kuba@kernel.org Reviewed-by: Eric Dumazet edumazet@google.com Reviewed-by: Sabrina Dubroca sd@queasysnail.net Link: https://patch.msgid.link/20250404180334.3224206-1-kuba@kernel.org Signed-off-by: Paolo Abeni pabeni@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- net/tls/tls_main.c | 6 ++++++ 1 file changed, 6 insertions(+)
diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index 4a3bf8528da7c..ba170f1f38a4c 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -626,6 +626,11 @@ static int tls_setsockopt(struct sock *sk, int level, int optname, return do_tls_setsockopt(sk, optname, optval, optlen); }
+static int tls_disconnect(struct sock *sk, int flags) +{ + return -EOPNOTSUPP; +} + struct tls_context *tls_ctx_create(struct sock *sk) { struct inet_connection_sock *icsk = inet_csk(sk); @@ -720,6 +725,7 @@ static void build_protos(struct proto prot[TLS_NUM_CONFIG][TLS_NUM_CONFIG], prot[TLS_BASE][TLS_BASE] = *base; prot[TLS_BASE][TLS_BASE].setsockopt = tls_setsockopt; prot[TLS_BASE][TLS_BASE].getsockopt = tls_getsockopt; + prot[TLS_BASE][TLS_BASE].disconnect = tls_disconnect; prot[TLS_BASE][TLS_BASE].close = tls_sk_proto_close;
prot[TLS_SW][TLS_BASE] = prot[TLS_BASE][TLS_BASE];