On 10/29/24 4:07 PM, Stanislav Fomichev wrote:
On 10/29, zijianzhang@xxxxxxxxxxxxx wrote:
From: Zijian Zhang <zijianzhang@xxxxxxxxxxxxx>
As the introduction of the support for vsock and unix sockets in sockmap,
tls_sw_has_ctx_tx/rx cannot presume the socket passed in must be inet.
Otherwise, tls_get_ctx may return an invalid pointer and result in page
fault in function tls_sw_ctx_rx.
BUG: unable to handle page fault for address: 0000000000040030
Workqueue: vsock-loopback vsock_loopback_work
RIP: 0010:sk_psock_strp_data_ready+0x23/0x60
Call Trace:
? __die+0x81/0xc3
? no_context+0x194/0x350
? do_page_fault+0x30/0x110
? async_page_fault+0x3e/0x50
? sk_psock_strp_data_ready+0x23/0x60
virtio_transport_recv_pkt+0x750/0x800
? update_load_avg+0x7e/0x620
vsock_loopback_work+0xd0/0x100
process_one_work+0x1a7/0x360
worker_thread+0x30/0x390
? create_worker+0x1a0/0x1a0
kthread+0x112/0x130
? __kthread_cancel_work+0x40/0x40
ret_from_fork+0x1f/0x40
Fixes: 0608c69c9a80 ("bpf: sk_msg, sock{map|hash} redirect through ULP")
Fixes: e91de6afa81c ("bpf: Fix running sk_skb program types with ktls")
Signed-off-by: Zijian Zhang <zijianzhang@xxxxxxxxxxxxx>
---
include/net/tls.h | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/include/net/tls.h b/include/net/tls.h
index 3a33924db2bc..a65939c7ad61 100644
--- a/include/net/tls.h
+++ b/include/net/tls.h
@@ -390,8 +390,12 @@ tls_offload_ctx_tx(const struct tls_context *tls_ctx)
static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
{
- struct tls_context *ctx = tls_get_ctx(sk);
+ struct tls_context *ctx;
+
+ if (!sk_is_inet(sk))
+ return false;
+ ctx = tls_get_ctx(sk);
if (!ctx)
return false;
return !!tls_sw_ctx_tx(ctx);
@@ -399,8 +403,12 @@ static inline bool tls_sw_has_ctx_tx(const struct sock *sk)
static inline bool tls_sw_has_ctx_rx(const struct sock *sk)
{
- struct tls_context *ctx = tls_get_ctx(sk);
+ struct tls_context *ctx;
+
+ if (!sk_is_inet(sk))
+ return false;
+ ctx = tls_get_ctx(sk);
if (!ctx)
return false;
return !!tls_sw_ctx_rx(ctx);
This seems like a strange place to fix it. Why does tls_get_ctx return
invalid pointer for non-tls/ulp sockets? Shouldn't it be NULL?
Is sockmap even supposed to work with vsock?
Here is my understanding, please correct me if I am wrong :)
```
static inline struct tls_context *tls_get_ctx(const struct sock *sk)
{
const struct inet_connection_sock *icsk = inet_csk(sk);
return (__force void *)icsk->icsk_ulp_data;
}
```
tls_get_ctx assumes the socket passed is icsk_socket. However, unix
and vsock do not have inet_connection_sock, they have unix_sock and
vsock_sock. The offset of icsk_ulp_data are meaningless for them, and
they might point to some other values which might not be NULL.
Afaik, sockmap started to support vsock in 634f1a7110b4 ("vsock: support
sockmap"), and support unix in 94531cfcbe79 ("af_unix: Add
unix_stream_proto for sockmap").
If the above is correct, I find that using inet_test_bit(IS_ICSK, sk)
instead of sk_is_inet will be more accurate.
