| Message ID | 20180816194910.9040-2-daniel@iogearbox.net |
|---|---|
| State | Accepted, archived |
| Delegated to: | BPF Maintainers |
| Headers | show |
| Series | BPF sockmap and ulp fixes | expand |
On Thu, Aug 16, 2018 at 12:49 PM, Daniel Borkmann <daniel@iogearbox.net> wrote: > Lets not turn the TCP ULP lookup into an arbitrary module loader as > we only intend to load ULP modules through this mechanism, not other > unrelated kernel modules: > > [root@bar]# cat foo.c > #include <sys/types.h> > #include <sys/socket.h> > #include <linux/tcp.h> > #include <linux/in.h> > > int main(void) > { > int sock = socket(PF_INET, SOCK_STREAM, 0); > setsockopt(sock, IPPROTO_TCP, TCP_ULP, "sctp", sizeof("sctp")); > return 0; > } > > [root@bar]# gcc foo.c -O2 -Wall > [root@bar]# lsmod | grep sctp > [root@bar]# ./a.out > [root@bar]# lsmod | grep sctp > sctp 1077248 4 > libcrc32c 16384 3 nf_conntrack,nf_nat,sctp > [root@bar]# > > Fix it by adding module alias to TCP ULP modules, so probing module > via request_module() will be limited to tcp-ulp-[name]. The existing > modules like kTLS will load fine given tcp-ulp-tls alias, but others > will fail to load: > > [root@bar]# lsmod | grep sctp > [root@bar]# ./a.out > [root@bar]# lsmod | grep sctp > [root@bar]# > > Sockmap is not affected from this since it's either built-in or not. > > Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") > Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> > Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Song Liu <songliubraving@fb.com> > --- > include/net/tcp.h | 4 ++++ > net/ipv4/tcp_ulp.c | 2 +- > net/tls/tls_main.c | 1 + > 3 files changed, 6 insertions(+), 1 deletion(-) > > diff --git a/include/net/tcp.h b/include/net/tcp.h > index d196901..770917d 100644 > --- a/include/net/tcp.h > +++ b/include/net/tcp.h > @@ -2065,6 +2065,10 @@ int tcp_set_ulp_id(struct sock *sk, const int ulp); > void tcp_get_available_ulp(char *buf, size_t len); > void tcp_cleanup_ulp(struct sock *sk); > > +#define MODULE_ALIAS_TCP_ULP(name) \ > + __MODULE_INFO(alias, alias_userspace, name); \ > + __MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name) > + > /* Call BPF_SOCK_OPS program that returns an int. If the return value > * is < 0, then the BPF op failed (for example if the loaded BPF > * program does not support the chosen operation or there is no BPF > diff --git a/net/ipv4/tcp_ulp.c b/net/ipv4/tcp_ulp.c > index 622caa4..7dd44b6 100644 > --- a/net/ipv4/tcp_ulp.c > +++ b/net/ipv4/tcp_ulp.c > @@ -51,7 +51,7 @@ static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name) > #ifdef CONFIG_MODULES > if (!ulp && capable(CAP_NET_ADMIN)) { > rcu_read_unlock(); > - request_module("%s", name); > + request_module("tcp-ulp-%s", name); > rcu_read_lock(); > ulp = tcp_ulp_find(name); > } > diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c > index b09867c..93c0c22 100644 > --- a/net/tls/tls_main.c > +++ b/net/tls/tls_main.c > @@ -45,6 +45,7 @@ > MODULE_AUTHOR("Mellanox Technologies"); > MODULE_DESCRIPTION("Transport Layer Security Support"); > MODULE_LICENSE("Dual BSD/GPL"); > +MODULE_ALIAS_TCP_ULP("tls"); > > enum { > TLSV4, > -- > 2.9.5 >
diff --git a/include/net/tcp.h b/include/net/tcp.h index d196901..770917d 100644 --- a/include/net/tcp.h +++ b/include/net/tcp.h @@ -2065,6 +2065,10 @@ int tcp_set_ulp_id(struct sock *sk, const int ulp); void tcp_get_available_ulp(char *buf, size_t len); void tcp_cleanup_ulp(struct sock *sk); +#define MODULE_ALIAS_TCP_ULP(name) \ + __MODULE_INFO(alias, alias_userspace, name); \ + __MODULE_INFO(alias, alias_tcp_ulp, "tcp-ulp-" name) + /* Call BPF_SOCK_OPS program that returns an int. If the return value * is < 0, then the BPF op failed (for example if the loaded BPF * program does not support the chosen operation or there is no BPF diff --git a/net/ipv4/tcp_ulp.c b/net/ipv4/tcp_ulp.c index 622caa4..7dd44b6 100644 --- a/net/ipv4/tcp_ulp.c +++ b/net/ipv4/tcp_ulp.c @@ -51,7 +51,7 @@ static const struct tcp_ulp_ops *__tcp_ulp_find_autoload(const char *name) #ifdef CONFIG_MODULES if (!ulp && capable(CAP_NET_ADMIN)) { rcu_read_unlock(); - request_module("%s", name); + request_module("tcp-ulp-%s", name); rcu_read_lock(); ulp = tcp_ulp_find(name); } diff --git a/net/tls/tls_main.c b/net/tls/tls_main.c index b09867c..93c0c22 100644 --- a/net/tls/tls_main.c +++ b/net/tls/tls_main.c @@ -45,6 +45,7 @@ MODULE_AUTHOR("Mellanox Technologies"); MODULE_DESCRIPTION("Transport Layer Security Support"); MODULE_LICENSE("Dual BSD/GPL"); +MODULE_ALIAS_TCP_ULP("tls"); enum { TLSV4,
Lets not turn the TCP ULP lookup into an arbitrary module loader as we only intend to load ULP modules through this mechanism, not other unrelated kernel modules: [root@bar]# cat foo.c #include <sys/types.h> #include <sys/socket.h> #include <linux/tcp.h> #include <linux/in.h> int main(void) { int sock = socket(PF_INET, SOCK_STREAM, 0); setsockopt(sock, IPPROTO_TCP, TCP_ULP, "sctp", sizeof("sctp")); return 0; } [root@bar]# gcc foo.c -O2 -Wall [root@bar]# lsmod | grep sctp [root@bar]# ./a.out [root@bar]# lsmod | grep sctp sctp 1077248 4 libcrc32c 16384 3 nf_conntrack,nf_nat,sctp [root@bar]# Fix it by adding module alias to TCP ULP modules, so probing module via request_module() will be limited to tcp-ulp-[name]. The existing modules like kTLS will load fine given tcp-ulp-tls alias, but others will fail to load: [root@bar]# lsmod | grep sctp [root@bar]# ./a.out [root@bar]# lsmod | grep sctp [root@bar]# Sockmap is not affected from this since it's either built-in or not. Fixes: 734942cc4ea6 ("tcp: ULP infrastructure") Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> --- include/net/tcp.h | 4 ++++ net/ipv4/tcp_ulp.c | 2 +- net/tls/tls_main.c | 1 + 3 files changed, 6 insertions(+), 1 deletion(-)