| Message ID | 20250213-vsock-listen-sockmap-nullptr-v1-2-994b7cd2f16b@rbox.co |
|---|---|
| State | New |
| Headers | show |
| Series | [net,1/4] sockmap, vsock: For connectible sockets allow only connected | expand |
On 2/17/25 11:59, Stefano Garzarella wrote: > On Thu, Feb 13, 2025 at 12:58:50PM +0100, Michal Luczaj wrote: >> In the spirit of commit 91751e248256 ("vsock: prevent null-ptr-deref in >> vsock_*[has_data|has_space]"), armorize the "impossible" cases with a >> warning. >> >> Fixes: 634f1a7110b4 ("vsock: support sockmap") >> Signed-off-by: Michal Luczaj <mhal@rbox.co> >> --- >> net/vmw_vsock/af_vsock.c | 3 +++ >> net/vmw_vsock/vsock_bpf.c | 2 +- >> 2 files changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c >> index 53a081d49d28ac1c04e7f8057c8a55e7b73cc131..7e3db87ae4333cf63327ec105ca99253569bb9fe 100644 >> --- a/net/vmw_vsock/af_vsock.c >> +++ b/net/vmw_vsock/af_vsock.c >> @@ -1189,6 +1189,9 @@ static int vsock_read_skb(struct sock *sk, skb_read_actor_t read_actor) >> { >> struct vsock_sock *vsk = vsock_sk(sk); >> >> + if (WARN_ON_ONCE(!vsk->transport)) >> + return -ENODEV; >> + >> return vsk->transport->read_skb(vsk, read_actor); >> } >> >> diff --git a/net/vmw_vsock/vsock_bpf.c b/net/vmw_vsock/vsock_bpf.c >> index f201d9eca1df2f8143638cf7a4d08671e8368c11..07b96d56f3a577af71021b1b8132743554996c4f 100644 >> --- a/net/vmw_vsock/vsock_bpf.c >> +++ b/net/vmw_vsock/vsock_bpf.c >> @@ -87,7 +87,7 @@ static int vsock_bpf_recvmsg(struct sock *sk, struct msghdr *msg, >> lock_sock(sk); >> vsk = vsock_sk(sk); >> >> - if (!vsk->transport) { >> + if (WARN_ON_ONCE(!vsk->transport)) { >> copied = -ENODEV; >> goto out; >> } > > I'm not a sockmap expert, so I don't understand why here print an > error. > > Since there was already a check, I expected it to be a case that can > happen, but instead calling `rcvmsg()` on a socket not yet connected is > impossible? That's right, calling vsock_bpf_recvmsg() on a not-yet-connected connectible socket is impossible since PATCH 1/4 of this series. That is because to reach vsock_bpf_recvmsg(), you must have sock's proto replaced in vsock_bpf_update_proto(). For that you need to run sock_map_init_proto(), which you can't because the patched sock_map_sk_state_allowed() will stop you.
diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c index 53a081d49d28ac1c04e7f8057c8a55e7b73cc131..7e3db87ae4333cf63327ec105ca99253569bb9fe 100644 --- a/net/vmw_vsock/af_vsock.c +++ b/net/vmw_vsock/af_vsock.c @@ -1189,6 +1189,9 @@ static int vsock_read_skb(struct sock *sk, skb_read_actor_t read_actor) { struct vsock_sock *vsk = vsock_sk(sk); + if (WARN_ON_ONCE(!vsk->transport)) + return -ENODEV; + return vsk->transport->read_skb(vsk, read_actor); } diff --git a/net/vmw_vsock/vsock_bpf.c b/net/vmw_vsock/vsock_bpf.c index f201d9eca1df2f8143638cf7a4d08671e8368c11..07b96d56f3a577af71021b1b8132743554996c4f 100644 --- a/net/vmw_vsock/vsock_bpf.c +++ b/net/vmw_vsock/vsock_bpf.c @@ -87,7 +87,7 @@ static int vsock_bpf_recvmsg(struct sock *sk, struct msghdr *msg, lock_sock(sk); vsk = vsock_sk(sk); - if (!vsk->transport) { + if (WARN_ON_ONCE(!vsk->transport)) { copied = -ENODEV; goto out; }
In the spirit of commit 91751e248256 ("vsock: prevent null-ptr-deref in vsock_*[has_data|has_space]"), armorize the "impossible" cases with a warning. Fixes: 634f1a7110b4 ("vsock: support sockmap") Signed-off-by: Michal Luczaj <mhal@rbox.co> --- net/vmw_vsock/af_vsock.c | 3 +++ net/vmw_vsock/vsock_bpf.c | 2 +- 2 files changed, 4 insertions(+), 1 deletion(-)